Long Lifetime Laser Diode Packaging

Abstract

There are provided high power, high brightness solid-state laser systems that maintain initial beam properties, including power levels, and do not have degradation of performance or beam quality, for at least 10,000 hours of operation. There are provided high power, high brightness solid-state laser systems containing Oxygen in their internal environments and which are free from siloxanes.

Claims

1. A sealed container packaging an individual laser diode for providing a laser beam; the sealed container defining an internal cavity and internal surfaces; wherein the internal surfaces are free of Silicone contaminates, whereby SiO.sub.2 is not formed during operation of the laser diode; and wherein the internal cavity contains a means for preventing the formation of Carbon contaminates on the internal surfaces.

2. A sealed container packaging a plurality of individual laser diodes for providing a laser beam; the sealed container defining an internal cavity and internal surfaces; wherein the internal surfaces are essentially free of Silicone contaminates, whereby SiO.sub.2 is not formed during operation of the laser diode; and wherein the internal cavity contains a means to prevent the formation of Carbon contaminates on the internal surfaces.

3. The sealed container of claim 1, wherein the laser beam is a blue laser beam.

4. The sealed container of claim 1, wherein the laser beam is a green laser beam.

5. The sealed container of claim 2, wherein the laser beam is a blue laser beam.

6. The sealed container of claim 2, wherein the laser beam is a green laser beam.

7. The sealed container of claim 1, wherein the laser beam has a power density of 0.5 MW/cm.sup.2 to 1,000 MW/cm.sup.2, at least about 1 MW/cm.sup.2, at least about 5 MW/cm.sup.2, or least about 10 MW/cm.sup.2.

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12. The sealed containers of claim 1, wherein the sealed container has an 80% laser lifetime of at least 5,000 hours.

13. The sealed containers of claim 2, wherein the sealed container has an 80% laser lifetime of at least 10,000 hours.

14. The sealed containers of claim 1, wherein the sealed container has an 80% laser lifetime comprising 5,000 hours to 10,000 hours.

15. The sealed containers of claim 2, wherein the degradation rate is 2.5% per khrs or less.

16. The sealed containers of claim 1, wherein the degradation rate is 2.0% per khrs or less.

17. The sealed containers of claim 2, wherein the degradation rate is 1.5% per khrs or less.

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21. The sealed containers of claim 1, wherein the container is or comprises a TO-9 Can.

22. A high power, high brightness solid-state laser device package, for integration into laser systems providing a high-quality blue laser beam over long periods of time without substantial degradation of the laser beam properties, the package comprising: a. a housing, the housing defining an internal cavity; wherein the internal cavity is isolated from an environment that is external to the housing; b. the housing comprising a window, wherein the window defines a portion of the internal cavity; c. a solid-state device for propagating a laser beam from a propagation surface of the solid-state device along a laser beam path, wherein the laser beam has a wavelength in the range of 410 nm to 500 nm; and wherein the laser beam has a power density of at least about 0.5 MW/cm.sup.2 at the propagation surface; d. the window in optical communication with the solid-state device and on the laser beam path; e. wherein the solid-state device is located within the housing and in the internal cavity and wherein an inner surface of the window is not exposed to the external environment, whereby the solid-state device and the inner surface of the window are isolated from the external environment; f. whereby the laser beam is transmitted from the propagation surface through the window into the external environment along the laser beam path; g. the internal cavity being free from sources of silicon based contaminates, whereby during operation of the solid-state device SiO.sub.2 production within the internal cavity is avoided; whereby the internal cavity avoids SiO.sub.2 buildup; thereby the degradation rate of the beam properties is 2.3% per khrs or less; and, h. wherein the internal cavity comprises a gas comprising at least 1% Oxygen; whereby during operation of the solid-state device CO.sub.2 is created within the internal cavity from carbon based contaminates, whereby the propagation surface of solid-state device and an inner surface of the window remain free of Carbon buildup.

23. The package of claim 22, wherein the sealed container has an 80% laser lifetime of at least 5,000 hours.

24. The package of claim 22, wherein the sealed container has an 80% laser lifetime of at least 10,000 hours.

25. The package of claim 22, wherein the sealed container has an 80% laser lifetime comprising 5,000 hours to 10,000 hours.

26. The package of claim 22, wherein the diode laser is a TO-9 Can.

27. The package of claim 22, wherein the power density is at least about 10 MW/cm.sup.2, the laser beam has a power of at least about 2 W, the degradation rate is 2.0% per khrs of less.

28. The package of claim 22, wherein the power density is at least about 5 MW/cm.sup.2, the laser beam has a power of at least about 1.5 W, the degradation rate is 1.8% per khrs of less.

29. The package of claim 22, wherein the power density is at least about 15 MW/cm.sup.2, the laser beam has a power of at least about 5 W, the degradation rate is 2.3% per khrs of less.

30. The package of claim 22, comprising at least 10% Oxygen.

31. The package of claim 22, comprising at least 40% Oxygen.

32. The package of claim 22, comprising at least 60% Oxygen.

33. (canceled)

34. The package of claim 22, wherein the sources of Carbon based contaminates is selected from the group consisting of solvent residues, oils, fingerprints and hydrocarbons.

35. The sealed container of claim 1, wherein the Silicon contaminates are less than 0.01 g., less than 0.001 g., less than 0.0001 g., and less than 0.00001 g., or less than 0.000001 g., within the package or sealed container.

36. The sealed container of claim 2, wherein the Silicon contaminates are less than 0.01 ppm Silicon, less than 0.001 ppm Silicon, less than 0.0001 ppm Silicon, or less than 0.00001 ppm Silicon, within the package or sealed container.

37. The package of claim 22, wherein the power density is at least about 10 MW/cm.sup.2, the laser beam has a power of at least about 2 W, the degradation rate is 2.0% per khrs of less.

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44. A method of operating a sealed container packaging an individual laser diode to propagate a laser beam having beam properties defining a nominal power and a nominal BPP, wherein the sealed container comprises a window and defines an internal cavity and internal surfaces; the method comprising: a. propagating the laser beam from a facet of the laser diode through the cavity and out the window away from the sealed container for a run time comprising at total of at least 5,000 hours; b. wherein no SiO.sub.2 is formed on the internal surfaces of the cavity during propagation of the laser diode; c. wherein CO2 is formed within the internal cavity during propagation of the laser diode; and, d. wherein during the run time the laser beam maintains at least 80% of its nominal power and at least 80% of its nominal BPP, whereby the laser beam properties are minimally degraded over the run time.

45. A method of operating a sealed container packaging a plurality of individual laser diodes to propagate a combined laser beam having beam properties defining a nominal power and a nominal BPP, wherein the sealed container comprises a window and defines an internal cavity and internal surfaces; the method comprising: a. propagating the individual laser beams from facets of the laser diodes; combining the individual laser beams to form the combined laser beam within the cavity and directing the combined laser beam out the window away from the sealed container for a run time comprising at total of at least 5,000 hours; b. wherein no SiO.sub.2 is formed on the internal surfaces of the cavity during propagation of the laser diode; c. wherein CO2 is formed within the internal cavity during propagation of the laser diode; and, d. wherein during the run time the combined laser beam maintains at least 80% of its nominal power and at least 80% of its nominal BPP, whereby the beam properties are minimally degraded over the run time.

46. The method of claim 44, wherein the laser beam is a blue laser beam.

47. The method of claim 45, wherein the laser beam is a green laser beam.

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Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] FIG. 1 is a graph of output power vs time, providing a degradation curve showing the degradation rate, for a high power blue laser system.

[0034] FIG. 2 is a graph of embodiments of improved power output vs time, providing a degradation curve showing the degradation rate, for 4 different high power blue laser systems in accordance with the present inventions.

[0035] FIG. 3 is a schematic diagram of a laser system in accordance with the present inventions.

[0036] FIG. 4 is a schematic diagram of a laser system in accordance with the present inventions.

[0037] FIG. 5 is a schematic diagram of a laser system in accordance with the present inventions.

[0038] FIG. 6 is a schematic diagram of a laser system in accordance with the present inventions.

[0039] FIG. 7 is a graph of the laser power in Watts (as a percentage) vs time of operation (hours) of an embodiment of a laser system in accordance with the present inventions.

[0040] FIG. 8 is a graph of the laser power (Watts) vs time of operation (hours) of an embodiment of a laser system in accordance with the present inventions.

[0041] FIG. 9 is a schematic diagram of a diode laser illustrating the typical areas where contamination deposits can occur but are avoided by embodiments of extended lifetime lasers in accordance with the present inventions.

[0042] FIG. 10 is a schematic of a diode laser in a package providing an extended lifetime in accordance with the present inventions.

[0043] FIG. 11 is a schematic of a laser diode bar in a package providing an extended lifetime in accordance with the present inventions.

[0044] FIG. 12 is a cross sectional schematic of an embodiment of a TO-9 Can laser diode in accordance with the present inventions.

[0045] FIG. 13 is an illustration of an embodiment of the mounting of the TO-9 Can of FIG. 12 in an embodiment of a multi-laser package in accordance with the present inventions.

[0046] FIG. 14 is an illustration of an embodiment of the mounting of the TO-9 Can of FIG. 12 in an embodiment of a multi-laser package in accordance with the present inventions.

[0047] FIG. 15A is a perspective view of an embodiment of a multiple diode laser package in accordance with the present inventions.

[0048] FIG. 15B is a plan view of the package of FIG. 15A.

[0049] FIG. 15C is a cross sectional view of the package of FIG. 15A.

[0050] FIG. 16A is a plan view schematic of a multiple diode laser package in accordance with the present inventions. is

[0051] FIG. 16B is a cross sectional view of the package of FIG. 16A.

[0052] FIG. 17A is a plan view schematic of a multiple diode laser package in accordance with the present inventions. is

[0053] FIG. 17B is a cross sectional view of the package of FIG. 17A.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0054] The present inventions generally relate to lasers that produce laser beams of high quality and high reliability in the UV, blue and green wavelength ranges.

[0055] In embodiments the present inventions relate to lasers, laser packages and housing that produce blue laser beams of high quality, high reliability and long lifetimes.

[0056] In embodiments, there is generally provided laser systems, and solid-state laser packaging for such systems, in the wavelength range of about 400 nm to about 500 nm, having a lifetime of at least 5,000 hours.

[0057] Although this Specification primarily focusses on wavelengths of 500 nm, this is merely illustrative, it being understood that the packaging, assembly techniques, and cleaning techniques provided are applicable to blue, blue-green, green, shorter wavelength, and potentially other wavelength laser systems, and in particular, high brightness, high power systems.

[0058] Typically, the output power of blue laser diode emitters is generally about 5 W per diode, and typically less than 10 W per diode, although higher powers may be possible. High power blue laser systems are obtained by combining beams from multiple emitters, e.g., diodes. The combination of these blue laser beams can be from single emitters, bars of emitters and combinations and variations of these. The laser beams from these emitters are combined by using, for example, combinations of spatial, spectral, coherent and polarization methods. Examples of these beam combining systems are taught and disclosed in US Patent Publication Nos. 2016/0322777, 2018/0375296, 2016/0067827, 2019/0273365, and 2020/0086388, and U.S. patent application Ser. No. 16/695,090 filed Nov. 25, 2019, the entire disclosure of each of which is incorporated herein by reference.

[0059] Generally, the combination of these beams from the multiple emitters, involves the use of passive optical elements to collimate and combine the beams, such as lenses, mirrors, gratings, waveplates. Raman conversion may also be used for beam combination. High brightness sources are needed for most industrial applications such as welding, brazing or additive manufacturing; these typically have a very short focal length lens placed in close proximity to the laser emitter, inside the same package. In the following, the components in the package refer to any element that forms the laser assembly; they are grouped as the optically functional components (like lenses, gratings, mirrors, waveplates, windows), the mechanical components (such as package housing, spacers, mounts) and the positioning components (for example adhesives, solders, mechanical hardware).

[0060] Laser diode manufacturers have made advances in the design and manufacturing of blue laser diodes to ensure high reliability of the emitters themselves. In the same way, reliable dielectric coatings are available that provide the desired reflectivity at the blue wavelength while being compatible with the typical intensity of the blue laser diode sources. However, prior to the present inventions, high power blue laser diode systems lacked the level of reliability required for use in industrial applications, and in particular for cost effective use in industrial applications. It has been discovered that this results from the presences of sources of Silicon and Carbon based contaminants that are typically introduced into the system during assembly of the system; and which, as discussed below, during laser operation form deposits on the active optical surfaces of the system, degrading laser performance and shorting the lifetime of the laser and laser system.

[0061] It has been discovered that a limiting factor, and in embodiments the main limiting factors for the lifetime of high-power blue laser diode systems are related to packaging of the system and in particular of the diode, the optical assembly and both the diode and optical assembly. Contamination by volatile organic compounds, like hydrocarbons or poly-siloxanes, can result from outgassing of adhesives, or other materials in the package. Other common sources of contamination include airborne contaminants present in the environment during the assembly process, residues from storage containers of any of the components, surface contaminants present on the tools used for the process, and in general any surface that comes in contact with any of the materials used in the package. In general, it is presently believed that any organic compound that has a vapor pressure sufficient to generate trace amounts of gaseous contaminants in the range of temperature associated with normal operation of the laser is potentially harmful to laser system reliability. It is theorized that the short wavelength of the blue lasers, and shorter wavelength lasers, allows two-photon processes to efficiently generate reactive species in the package, like atomic oxygen, hydroxyls, or ozone. These reactive species then have a gas phase reaction with the volatile organic contaminants leading to deposits or buildup of various solids on optical surfaces in the beam path, i.e., optically active surfaces, which increases the optical losses, reduces the system output, and degrades the properties of the laser beam over time. It is theorized that these deposits and buildup reduce, and greatly reduce, the lifetime of a system. It is further theorized that these deposits and buildup are a primary reason for reaching the end of the lifetime of a system.

[0062] Thus, embodiments of the present inventions, it is theorized, minimize, reduce, and avoid these buildups and provide blue, and potentially green, laser systems having the high reliability, small degradation rates, and long lifetimes, as described and taught in this Specification.

[0063] Turning to FIG. 1 there is shown a graph of power output vs time for a typical blue laser system that does not reduce the amount of Silicon contaminates. Thus, this system contains sources of silicon based contaminates and thus is not free from sources of silicon based contaminates. P.sub.i is the initial power 101, which is also the nominal value, Pf is the final power 102, which corresponds to 88.73% of the nominal value at about 150 hours of operating time.

[0064] Comparing the poor performance of the system of FIG. 1, with the performance of embodiments of the present inventions, as shown in FIG. 2, the considerable increase in the lifetime of the lasers using embodiments of the present inventions is shown. FIG. 2 shows a four plots (lines) for power output vs operating time of four laser 201, 202, 203, 204, in accordance with embodiments of the present inventions. At the 400 hour point all of these lasers are showing greater than 98% laser lifetimes.

[0065] Thus, turning to FIG. 3 there is a schematic block diagram of high power, high brightness blue laser system 300. The system 300 has a collection of laser diodes, e.g., emitters, 301. The laser diodes 301 have various mechanical components 320 to mount, position and hold the diodes. These mechanical components 320 are directly or indirectly physically associated with, e.g., attached to, affixed to, etc., a base 321. The base 321 is mechanically associated with a cover 322, which has an inner surface 323. The cover 322 is attached to the base 321 and sealed to the base to form housing 326 that houses or contains an internal cavity 334, that is isolated from the exterior environment 335. There are optical components 302 that are directly or indirectly physically associated with the further mechanical components 324, which are directly or indirectly physically associated with the base 321. The laser diodes 301 and the optical components 302 are contained within the internal cavity 334 are isolated from the exterior environment 335 by the housing 326.

[0066] Each of the laser diodes has a facet, e.g., 304 (only one is shown for clarity) from which the blue laser beams are propagated. The laser beam 350 is propagated along laser beam path 350a (it being understood that the laser beam travels along the laser beam path, and thus is coincident with the laser beam path) to the optics 302, and then to, and through a window 325 in housing 326. Thus, the laser beam is propagated through the internal cavity 334 and out of that cavity and into the exterior environment 335.

[0067] The internal cavity, of these embodiments, and thus the environment within that cavity and preferable all surfaces within that cavity, are free from sources of silicon based contaminates, such as siloxanes, polymerized siloxanes, linear siloxanes, cyclic siloxanes, cyclomethicones, and poly-siloxanes. In particular, in an embodiment, the surfaces and joints within the housing that are heated during operation, that are exposed to the laser beam, and preferably both, are free from sources of silicon based contaminates. By “free from” it is meant that the amount of contaminate present is so low as to render de minimis, and preferably zero, the amount of Silicon (or specified contaminant) released into the internal cavity during operation. In this manner, it is theorized that the reactive oxygen formed during propagation of the blue laser beam through the interior cavity will have, essentially no, and no Silicon available to react with, and thus, minimize the formation of SiO.sub.2, preferably avoid the formation of SiO.sub.2, and more preferably will not form SiO.sub.2, and, in turn, will minimize SiO.sub.2 deposits, avoid SiO.sub.2 deposits, and more preferably will not have SiO.sub.2 deposits forming on the optically active surfaces within the cavity. The amount of Silicon based contamination is avoided, and thus reduced to such a low level that any available Silicon for forming SiO.sub.2 is de minimis, negligible, or below the level that would cause laser degradate rates greater than the embodiments of the present systems. Generally, an optically active surface, is any surface that is contacted by the laser beam and is on the laser beam path, this would include facets, fiber faces, mirrors, lenses, windows, propagations surfaces, and transmission surfaces.

[0068] The internal cavity, of these embodiments, and thus the environment within that cavity, however, can contain sources of Carbon based contamination. Thus, all, or most, Carbon based contamination does not need to be removed during assembly, e.g., packaging, of the laser assembly or system. Such Carbon based contamination would include for example, cleaners, solvents, lubricants, oils, human finger prints and oils, and generally any other hydrocarbon source. The internal cavity contains gaseous oxygen, a source of gaseous Oxygen during operation (e.g., a port or flow line in the housing to supply Oxygen to the system during operation), or both. The Oxygen forms reactive atomic oxygen when exposed to the blue laser beam and this reactive Oxygen forms gaseous CO.sub.2 by reacting with any Carbon that is released from the Carbon based contamination sources, and thus, minimized, preferably avoids, and more preferably prevents, the deposit, deposition, or buildup of Carbon on the optically active surfaces within the internal cavity.

[0069] The internal cavity, of these various embodiments, can have from 1% to 100% Oxygen, from about 5% to about 80% Oxygen, from about 10% to about 50%, from about 30% to about 80% Oxygen, from about 5% to about 30% Oxygen, and the ambient amount of Oxygen present in air (e.g, the internal cavity can contain clean dry air). The other gases in the internal cavity can be, for example, Nitrogen.

[0070] The internal cavity, of these embodiments, can have less than 0.01 ppm Silicon, less than 0.001 ppm Silicon, less than 0.0001 ppm Silicon, and lessor amounts, present in, or available to, the internal cavity.

[0071] The combination of a blue laser beam, with one and preferably both of gaseous oxygen in the internal cavity, and the absence of sources of Silicon based contamination in the internal cavity, of the laser assembly provides assemblies that can have lifetimes (and also can be accurately characterized, marketed and labeled, as having such lifetimes) of from about 5,000 hours to about 100,000 hours, from about 10,000 hours to about 90,000 hours, from about 5,000 hours to about 50,000 hours, from about 30,000 hours to about 70,000 hours, at least about 20,000 hours, at least about 30,000 hours, at least about 40,000 hours, at least about 50,000 hours and longer times.

[0072] These various embodiments of laser systems or assemblies, having these high reliabilities, i.e., these long lifetimes, can provide or propagate blue laser beams (e.g., wavelength of from about 410 nm to about 500 nm, 410 nm to 500 nm, about 405-495 nm, 450 nm, about 450 nm, 460 nm, about 460 nm, 470 nm and about 470 nm). These blue laser beams can have bandwidths of from about 10 pm (picometer) to about 10 nm, about 5 nm, about 10 nm, about 20 nm, from about 10 nm to about 30 nm, from about 5 nm to about 40 nm, about 20 nm or less, about 30 nm or less, about 15 nm or less, about 10 nm or less, as well as greater and smaller values. These blue laser beams can have powers of from about 100 W (Watts) to about 100,000 W, from about 100 W to about 40,000 W, from about 100 W to about 1,000 W, about 200 W, about 250 W, about 500 W, about 1,000 W, about 10,000 W, at least about 100 W, at least about 200 W, at least about 500 W, at least about 1,000 W, and larger and smaller powers. For the packaging of individual diodes, these laser beams can have powers for from about 1 W to about 10 W, about 3 W, about 5 W, about 6 W and about 10 W and greater. These blue laser beams can have BPP of from about 5 mm mrad to about 50 mm mrad, less than about 40 mm mrad, less than about 30 mm mrad, less than about 20 mm mrad, less than about 15 mm mrad, less than about 10 mm mrad, 20 mm mrad and lower, and 15 mm mrad and lower, as well as greater and smaller values. For Raman laser based systems the BPP for these blue laser beams can be less than 5 mm mrad, less than 1 mm mrad, from about 0.1 to about 1 mm mrad, from about 0.1 to about 0.5 mm mrad, about 0.13 mm mrad, and about 0.15 mm mrad.

[0073] These laser beams for these various embodiments of laser systems and assemblies can have degradation rates of beam properties (e.g., power, BBP, bandwidth, or other properties of the beam, and combinations of one or more and all of these properties) of about 2.5% per khrs (1,000 hours) or less, about 2.3% per khrs or less, about 2.1% per khrs or less, about 2.0% per khrs or less, about 1.8% per khrs or less, from about 2.3% per khrs to about 1.5% per khrs, as well as, larger and smaller amounts. In preferred embodiments, these degradation rates are present starting at, based upon, the “normal values” of the properties for the laser, during the lifetime of the laser system, and both. In preferred embodiments these degradation rates are present over the entire lifetime of the system. In more preferred embodiments the laser systems will have a period of their lifetime when the degradation curve, i.e., the plot of the degradation vs time, is flat, i.e., the degradation rate is zero. This period of zero degradation can be from 1 hour to 500 hours and more, can be for a period that is 10% of the lifetime, 20% of the lifetime, 30% of the lifetime and more.

[0074] It should be noted that these contaminates (Silicon based and Carbon based) form when the lasers are operated at lower powers, as well as high power, over their entire operating range and rated powers. Thus, these degradation rates, unless expressly stated otherwise, are for operation of the laser at rated powers, within rated operating ranges, or at normal and establish operating ranges for such lasers.

[0075] It is theorized that there are two primary components that contribute to the buildup of deposits on the optically active surfaces, and thus, reduce the lifetime of blue laser systems. These components are Carbon and SiO.sub.2. Conventional thinking would suggest that any such deposit contributing components be reduced or eliminated during assembly and packaging. The present inventions go against these conventions, however, buy increasing the amount of Oxygen, which would potentially increase the amount of SiO.sub.2 buildup, in order to manage any residual hydrocarbon contamination. In this manner residual hydrocarbon contamination can be present, but the system avoids, and preferably poses no risk, to the system because of the elevated Oxygen levels. The amount of siloxanes are minimized and preferably eliminated. Thus, one of the components needed for SiO.sub.2 deposits or buildup is minimized or eliminated; enabling the oxygen to neutralize the hydrocarbon buildup and deposits by forming CO.sub.2 instead of the solid Carbon buildup or deposit material. In an embodiment the amount of hydrocarbon contaminates are preferably minimized and can be essentially eliminated.

[0076] There are a large number of different cleaning and assembly techniques and procedures known, such as clean room assembly and protocols, solvent washes, extractions, plasma cleaning and the like, that can be used to remove and avoid the presence of any source of Silicon based contamination, any source of Carbon based contamination and both. The present cleaning and assembly techniques, are an example of many different such techniques and combinations of these techniques, that have applicability to these laser systems; and will have applicability to blue laser systems, shorter wavelength systems, blue-green and green laser systems, and to the high power systems of the present embodiments. In embodiments of the assembly process for the present solid-state lasers, optical assemblies, laser systems and combinations and variations of these, various methods of cleaning and assembling components, can be used to minimize the detrimental effect of the various contamination phenomena that have been discovered for blue and green laser systems, as well as shorter wavelength systems. In embodiments, methods of cleaning and assembling optical components for blue laser systems, and systems having lower and higher wavelengths, are used to mitigate, minimize, or eliminate, the materials that degrade laser performance over time. These assembly processes for a such lasers, optical assemblies and systems address and solve the reliability shortcomings of prior systems. For example, in an embodiment a cleaning method is used to remove silicon based sources of contaminates, which operating methods in embodiments are configured to remove targeted contaminants at specific steps in the assembly process, at specific locations on the components and combinations and variations of these. This cleaning method can provide an embodiment of a package that houses the solid-state laser, optics assembly, laser system (e.g., laser and optics) or combinations of these, preferably having levels of silicon based contaminates that are not detectable by standard analytic techniques. Such packages, which include any of the present embodiments and Examples, can have amounts of silicon based contaminates that are lower than 0.01 g., lower than 0.001 g., lower than 0.0001 g., and lower than 0.00001 g., and lower than 0.000001 g., within the isolated environment of the package. Such packages, which include any of the present embodiments and Examples, can have amounts of silicon based contaminates in the internal cavity (as determined by ppm Silicon based on the constituents of the internal cavity environment, e.g., the gas contained within the internal environment) that are lower than 0.1 ppm Silicon, lower than 0.01 ppm Silicon, less than 0.001 ppm Silicon, lower than 0.0001 ppm Silicon, lower than 0.00001 ppm Silicon, and lower. These systems and methods can have one or more of the following features: wherein there is primarily removed volatile contaminants of poly-siloxanes; wherein there is provided the benefit of removing any residue volatile hydrocarbons; and wherein other operating parameters are selected to remove different contaminants.

[0077] In an embodiment of an assembly process, plasma cleaning is used, and in particular plasma cleaning removes trace amounts of contaminants from surfaces of the components in the package, to dislodge contamination or particulates, and for example larger amounts of this contamination or particulates. In an embodiment plasma cleaning is used with a precleaning step, in which precleaning of the surface with carefully selected solvents, both polar and non-polar are used. Preferably, the solvent is chosen so that its polarity matches that of the targeted contaminant. Thus, it is envisioned that multiple precleaning, cleaning and plasma cleaning steps can be performed, and that these steps can be tailored to specific contaminates.

[0078] In an embodiment of these assembly processes, system components are heated under reduced pressure for predetermined periods of time to remove residual traces of volatile contaminants, in order to accelerate the outgassing of all volatile components. This preheating step can be, and preferably is, used with the other assembly techniques disclose in the Specification. The operating conditions of temperature and pressure are chosen so that the vapor pressure of the target contaminant is higher than the actual pressure in the oven, while still being safe for the component. This step also ensures that any residue of solvents from the precleaning steps is removed from the component.

[0079] An embodiment of the assembly process defines a sequence of precleaning and cleaning, in which it is advantageous to measure the polar and non-polar components of the surface free energy of the parts to be cleaned at different stages of the cleaning process. This provides useful information to select the appropriate combination of solvents and the best gas mixture to target the actual contaminants to be removed. In embodiments a preferred sequence can be different for different components of the assembly, due to the various histories of fabrication, storage and handling of each part.

[0080] In an embodiment of the assembly process these cleaning techniques are performed just before packaging, or at the time of packaging, as an additional or secondary, or tertiary cleaning step, e.g., the final cleaning step. It being recognized that even with careful cleaning of the parts and tooling prior to performing the assembly, there exists the possibility that some contamination may be introduced in the package during the integration. This can come, for example, from airborne contaminants present in the assembly area; outgassing from the adhesives during curing is another source of contamination. Therefore, in an embodiment, a final cleaning of the assembly is performed just before sealing the package. The same cleaning methods can be used that are described herein for the individual components.

[0081] Turing to FIG. 9 there is shown a schematic diagram of a laser diode 1000. The diode has a transverse guiding ridge 1010, a front facet 1011, a mode 1012, and vertical confining layers 1013. The contaminants that are formed during operation typically build up along the laser diode vertical confining layer 1013, with the greatest contamination being deposited in the central region of the mode and typically decreasing with the mode intensity in the transverse direction. The embodiments of the present systems and methods provide systems that when operated avoid, minimize and preferably prevent this buildup, as well as other buildups and deposits from occurring.

[0082] In order to prevent the ingress of external contaminants, high power laser systems were typically sealed with an inert or protective atmosphere, e.g., atmospheres with little and preferably no Oxygen. This technique however has proven less than effective for blue laser systems, and ineffective for providing long lifetime blue laser systems. It is theorized that the prior use of inert atmosphere is ineffective for blue laser systems, as well as, ineffective for green laser systems, because of the contaminate dissociation effect discussed in this Specification, and it is theorized potentially other phenomenon both understood and not yet fully understood, but who's effects can be seen on the degradation of laser performance, during normal operation of these blue wavelength laser systems, as well as in green laser systems. Further, during operation of these systems the temperature inside the package increases, which also results in outgassing from any component in the assembly; thus, these trace amounts of contaminants, from thermal outgassing, can have a detrimental impact on the reliability of the system, which impact could in some situations be very detrimental.

[0083] Having discovered these problems with blue wavelength systems and it is theorized green laser systems as well as shorter wavelength systems, embodiments of the present inventions, provide among other things, examples for appropriate methods to precisely clean, assemble, and both clean and assemble, the system's package or housing, including the optical package (as well as the components within that package, including the solid state laser) during the assembly process and prevent these detrimental processes, and the degradation of the laser system, from taking place.

[0084] Another issue, in addition to volatile organic contaminants build up on optical surfaces in the beam path, is the build-up of Silicon Dioxide (SiO.sub.2) on the surface of the laser diode facet or other optical components. This build up of Silicon Dioxide results in a change in the coating reflectivity. In some cases the build up of the Silicon Dioxide changes the optical properties of the surface. The single blue laser diode prior to collimation has a very intense optical field at the surface of the laser diode itself. The power density at the facet can exceed 20 MW/cm.sup.2 peak due to modal filaments forming in the cavity. It has been discovered and theorized that this high power density is what drives the two photon reaction that dissociates the atmosphere in the package. Once dissociated, the free oxygen atoms rapidly combine with any free Silicon to form SiO.sub.2 at the facet. The SiO.sub.2 is deposited in a similar manner to Carbon gettering. The process of forming and depositing SiO.sub.2 can also proceed throughout other optics including the collimating optics, but due to the much lower power densities at the collimating optics, which can be on the order of a few kW/cm.sup.2, the deposition rate is 1,000× less than it is at the facets, but should still be taken in to consideration in the packaging, assembly and cleaning of the system.

[0085] The optically active surface of a solid-state laser device of the present systems and assemblies, from which the laser beam is propagated, e.g., a fiber face, a window, or a facet, can have a power density of at least about 0.5 MW/cm.sup.2, at least about 1 MW/cm.sup.2 (Mega Watt per centimeter squared), at least about 10 MW/cm.sup.2, at least about 20 MW/cm.sup.2, at least about 50 MW/cm.sup.2, at least about 100 MW/cm.sup.2, at least about 500 MW/cm.sup.2, about 1,000 MW/cm.sup.2 or lower, from about 10 MW/cm.sup.2 to about 100 MW/cm.sup.2, from about 5 MW/cm.sup.2 to about 20 MW/cm.sup.2, and from about 50 MW/cm.sup.2 to about 500 MW/cm.sup.2.

[0086] Any solid-state device for generating and propagating a laser beam can be used in the present systems and assemblies. Preferably, the solid-state device propagates a laser beam having a wavelength in the blue, blue-green and green wavelengths. Such solid-state laser devices can be, for example, laser diodes, fiber lasers, Raman fiber lasers, and Raman lasers based upon crystal (e.g., diamond, KGW, YVO4, Ba(NO3)2, etc.), and combinations and variations of one or more of these. The present systems can have one, two, three, five, ten, tens, a hundred, hundreds, and thousands of these solid-state devices having their beams combined to provide a high power, high brightness, laser beam for industrial and other applications.

[0087] It being understood that although this Specification focusses on complete laser systems, e.g., the solid-state laser device and the optics assembly are combined or integrated into one package or housing, its teaching have equal applicability to a stand-alone laser device with no optics, stand-alone optics assembly with no laser, and combinations and variations of these. These assemblies can be optically integrated, e.g., connected, in the field or before shipment by for example optical fibers with optical connectors.

[0088] Embodiments of the present laser devices and systems can be used for industrial applications such as for example for welding components, including components in electronic storage devices.

[0089] Since the process which creates the deposits on the facet, and other surfaces, of the laser diode, as well as other optically active surface, that lead to a loss of power are driven by a two photon process, the process can occur whether the devices are pulsed or run CW. A difference between the two operating modes is the rate of deposition of the SiO.sub.2 on the facet of the laser diode. The rate of deposition is directly proportional to the power density, the amount of deposit is the integral of this deposition rate over time. Consequently, if the deposition proceeds at a rate of 10 μm per 1,000 hours when operating CW, then it will only deposit 1 μm per 1,000 elapsed hours when operating at a 10% duty cycle. The deposition rate used here is merely an example, it is dependent on a number of other factors, primarily the amount of poly-siloxanes trapped in the package.

[0090] The comparative example given in FIGS. 1 and 2 uses a 60 W class blue laser composed on 20 single emitter diodes, each being collimated with a fast axis collimation lens to allow coupling into a delivery fiber. The lenses are attached with UV cured optical epoxy after submicron precision alignment. The package is made of gold-plated copper parts, using low temperature solders. The lenses are attached to glass mounts to match the coefficient of thermal expansion. This fairly simple assembly uses 3 different types of optical adhesives, 2 solders, 3 different types of glasses and 2 variations of the gold-plated copper. The assembly process involves multiple steps with different tools and storage containers for the components, which all provide opportunities to contaminate the surfaces. As a result, the interaction of the blue light with the contamination results in a rapid degradation of the output power from the device over time. This is illustrated in FIG. 1, which shows the performance of a typical device over extended testing; the expected lifetime of the laser is only around 200 hours (based on the definition of the time to reach 80% of nominal power), which is clearly not enough for industrial operation. The curve of FIG. 1 exhibits a very typical degradation rate of −100%/khrs, the corresponding lifetime of the device is less than 200 hours. The devices in both FIG. 1 and FIG. 2 had the same amount of Oxygen, 60%.

[0091] It has been discovered that there are at least two blue light interactions in the system that are detrimental to laser performance, and, in particular laser performance over time. First, the scattered light, reflected light and both, from the system heats the surfaces of the system increasing the outgassing from those surfaces and increasing the amount of volatilized contaminates, which in turn increases the amount of those contaminants that are deposited on, and degrade the performance of the laser system. Second, the laser beam, photolyze Oxygen through the two-photon process. The Oxygen atoms then react with both the organics in the package forming CO.sub.2, and the poly-siloxanes to from SiO.sub.2. In the case of the organics, the CO.sub.2 does not deposit on any surfaces and thus, their hydrocarbon source is less of a concern, but the poly-siloxanes are highly detrimental to the reliability. Consequently, the packaging environment (e.g., the inner environment of the housing containing the solid-state laser device, beam path and optics) is assembled and sealed to keep moisture and other contaminates from being introduced to achieve reliable operation.

[0092] FIG. 2 shows a graph of the variation of the output power from 5 samples of high-power blue laser devices that were packaged and assembled so as to be free from siloxanes in the internal environment and with an oxygen atmosphere. The laser devices used for the FIG. 2 tests were cleaned using an example of the cleaning sequences according to the present embodiments. The average degradation rate for these devices is −2.3% per khrs which is a 43× improvement of the lifetime compared to the devices of FIG. 1, which were free from siloxanes.

[0093] The following examples are provided to illustrate various embodiments of the present assembly methods, laser systems and operations. These examples are for illustrative purposes, may be prophetic, and should not be viewed as, and do not otherwise limit the scope of the present inventions.

Example 1

[0094] Turning to FIG. 10 there is shown a schematic diagram of the laser diode of FIG. 9 that is assembled into a sealed package that provides for extended lifetime of the diode. This package may then be later integrated into a laser system providing extended lifetime to that system. The diode 1000 is located inside of a sealed housing 1050, that forms the package or packaging for the laser diode, and is a laser diode assembly. The housing 1050 contains an internal environment 1051 that is isolated from an external environment 1052. The diode 1000 propagates a laser beam along a laser beam path 1056 through window 1055 and into the external environment 1052. The inner surface 1080 of the window 1055 is exposed to, and in contact with the internal environment 1051. All the surfaces in the internal cavity are free from silicon based contaminates. The laser beam is in the blue wavelength ranges and has a power of 3 W. The internal environment contains 60% Oxygen, whereby during operation of the solid-state device CO.sub.2 is created within the internal cavity from any carbon based contaminates that may be present after cleaning. The packaged assembly has a power degradation rate of less than 2.0% per khrs and an laser lifetime of at least 30,000 hours.

Example 1A

[0095] In embodiments of Example 1, the internal environment may contain from 1% to 80% Oxygen. The laser beam power may be from about 1 W to about 10 W, The power degradation rate may be less than 3% per khrs, less than 2.5% per khrs, less than 2% and less than 1.5% per khrs. The embodiment may have a laser lifetime of at least 20,000 hours, at least 40,000 hours, at least 50,000 hours, and at least 100,000 hours. In particular, the embodiments may have these lifetimes and degradation rates when assembled into a laser system, e.g., packaged with optics.

Example 1B

[0096] The laser diode of Example 1 is a TO-9 Can blue laser diode, an embodiment of which is shown in FIG. 12.

Example 1C

[0097] Turning to FIG. 11 there is shown a schematic diagram of 4 laser diodes that provide blue laser beams that are assembled into a sealed package that provides for extended lifetime of the diodes. This package may then be later integrated into a laser system providing extended lifetime to that system. The four laser diodes 1100a, 1100b, 1100c, 1100d are packed, e.g., contained, within a housing 1150 that is sealed, and thus, has an internal environment 1151. The housing 1150 protects, and isolates, the internal environment 1151 from an external environment 1152. The four laser diodes propagate blue laser beams having a power of about 5 W that travel along beam paths 1156a, 1156b, 1156c, 1156d. The laser beam travel along their respective beam paths exiting the housing 1150 through window 1155, where they travel into the external environment 1152. The inner surface 1180 of the window 1155 is exposed to, and in contact with, the internal environment 1151. Four separate windows, one for each diode may also be used. All the surfaces in the internal cavity are free from silicon based contaminates. The laser beams are each in the blue wavelength ranges, and each have a power of about 5 W. The internal environment contains 60% Oxygen, whereby during operation of the solid-state device CO.sub.2 is created within the internal cavity from any carbon based contaminates that remain after cleaning. The packaged assembly has a power degradation rate of less than 2.0% and a laser lifetime of at least 30,000 hours.

Example 1D

[0098] In embodiments of Example 1C, the internal environment may contain from 1% to 80% Oxygen. The laser beam power may be from about 1 W to about 10 W, The power degradation rate may be less than 3% per khrs, less than 2.5% per khrs, less than 2% per khrs and less than 1.5% per khrs. The embodiment may have a laser lifetime of at least 20,000 hours, at least 40,000 hours, at least 50,000 hours, and at least 100,000 hours. In particular, the embodiments may have these lifetimes and degradation rates when assembled into a laser system, e.g., packaged with optics.

Example 1E

[0099] The laser diodes of Example 1C are TO-9 Can blue laser diodes, an embodiment of which is shown in FIG. 12.

Example 2

[0100] Turning to FIG. 4 there is shown a schematic of an embodiment of a high power, high brightness solid-state laser assembly 400, or laser system, for providing a high-quality laser beam 450 over long periods of time without substantial degradation of the laser beam properties, the assembly having: a housing 426 the housing defining an internal cavity 434; wherein the internal cavity is isolated from an environment 435 that is external to the housing; a solid-state device 401 for propagating a laser beam 450 from a propagation surface 404 of the solid-state device along a laser beam path 450a, and wherein the laser beam has a power density of at least about 0.5 MW/cm.sup.2 at the propagation surface 404; an optics assembly 402, the optics assembly in optical communication with the solid-state device 401 and on the laser beam path 450a; wherein the solid-state device and the optics assembly are located within the housing 426 and in the internal cavity 434, whereby the solid-state device and the optics assembly are isolated from the external environment 435; the housing comprising a housing propagation surface 425, whereby the laser beam 450 is transmitted from the housing 426 into the external environment 435 along the laser beam path 450a; the housing propagation surface 425 in optical communication with the optics assembly 402 and on the laser beam path 450a; the laser beam upon exiting the housing propagation surface characterized by beam properties, the beam properties comprising: (i) a power of at least 100 W; and, (ii) a BPP of less than 40 mm mrad; and, the internal cavity being free from sources of silicon based contaminates, whereby during operation of the solid-state device SiO.sub.2 is not produced within the internal cavity; whereby the internal cavity remains free of SiO.sub.2 build up; thereby the degradation rate of the beam properties is 2.3% per khrs or less.

Example 3

[0101] In an embodiment the laser assembly of Example 2 has a solid-state device that produces a laser beam wherein the laser beam has a wavelength in the range of 410 nm to 500 nm.

Example 4

[0102] In an embodiment the laser assembly of Example 2 has a solid-state device that produces a laser beam wherein the laser beam has a wavelength in the range of 405 nm to 575 nm.

Example 5

[0103] In an embodiment the laser assembly of Example 2 has a solid-state device that produces a laser beam wherein the laser beam has a wavelength in the range of 500 nm to 575 nm.

Example 6

[0104] In embodiments of the laser assemblies of Examples 2, 3, 4 and 5 the solid-state device is a Raman fiber laser, a diode laser, a Raman laser based on a crystal and combinations and variations of one or more of these. The optics assembly has optical elements including collimating optics, focusing optics, lenses, mirrors, beam combining optics and combinations and variations of one or more of these. The beam properties further have a bandwidth of about 20 nm or less. The housing propagation surface is a window and a fiber face and combinations and variations of one or more of these. The BPP is less than about 15 mm mrad; and, the power density at the propagation surface is from about 1 MW/cm.sup.2 to about 1,000 MW/cm.sup.2.

Example 7

[0105] In embodiments of the laser assemblies of Examples 2, 3, 4, 5 and 6 the power of the laser beam is from about 100 W to about 1,000 W. The beam properties further comprise a bandwidth of about 20 nm or less; the power density at the propagation surface is from about 0.5 MW/cm.sup.2 to about 1,000 MW/cm.sup.2; and, the degradation rate of the beam properties is less than 2.0% per khrs.

Example 8

[0106] In embodiments of the laser assemblies of Examples 2-7 and 13-26, the internal cavity comprises a gas consisting of at least 1% Oxygen; whereby during operation of the solid-state device CO.sub.2 is created within the internal cavity from carbon based contaminates; whereby the propagation surface of the solid-state device and the optics assembly remain free of Carbon build up.

Example 9

[0107] In embodiments of the laser assemblies of Examples 2-7 and 13-26, the internal cavity comprises a gas consisting of at least 5% Oxygen; whereby during operation of the solid-state device CO.sub.2 is created within the internal cavity from carbon based contaminates; whereby the propagation surface of the solid-state device and the optics assembly remain free of Carbon build up.

Example 10

[0108] In embodiments of the laser assemblies of Examples 2-7 and 13-26, the internal cavity comprises a gas consisting of at least 10% Oxygen; whereby during operation of the solid-state device CO.sub.2 is created within the internal cavity from carbon based contaminates; whereby the propagation surface of the solid-state device and the optics assembly remain free of Carbon build up.

Example 11

[0109] In embodiments of the laser assemblies of Examples 2-7 and 13-26, the internal cavity comprises a gas consisting of at least 20% Oxygen; whereby during operation of the solid-state device CO.sub.2 is created within the internal cavity from carbon based contaminates; whereby the propagation surface of the solid-state device and the optics assembly remain free of Carbon build up.

Example 12

[0110] In embodiments of the laser assemblies of Examples 2-7 and 13-26, the internal cavity comprises a gas consisting of from about 5% to at least about 50% Oxygen; whereby during operation of the solid-state device CO.sub.2 is created within the internal cavity from carbon based contaminates; whereby the propagation surface of the solid-state device and the optics assembly remain free of Carbon build up.

Example 13

[0111] In embodiments of the laser assemblies of Examples 2-12 and 17-26, the degradation rate of the beam properties is 2.0% per khrs or less, from 2.0% to 1% per khrs.

Example 13A

[0112] The degradation rates of Example 13 are maintained for a 5,000 hr lifetime, for a 7,000 hr lifetime, and for a 10,000 hr lifetime.

Example 14

[0113] In embodiments of the laser assemblies of Examples 2-12 and 17-26, the degradation rate of the beam properties is 1.8% per khrs or less, from 1.8% to 0.8% per khrs.

Example 14A

[0114] The degradation rates of Example 14 are maintained for a 5,000 hr lifetime, for a 7,000 hr lifetime, and for a 10,000 hr lifetime.

Example 15

[0115] In embodiments of the laser assemblies of Examples 2-12 and 17-26, the assembly has, and is characterized by, having an extended lifetime of not less than 10,000 hours.

Example 16

[0116] In embodiments of the laser assemblies of Examples 2-12 and 17-26, the assembly is characterized by having an extended lifetime of not less than 5,000 hours.

Example 17

[0117] Turning to FIG. 5 there is provided a schematic of a high power, high brightness solid-state laser assembly 500, for providing a high-quality blue laser beam 550 over long periods of time without substantial degradation of the laser beam properties, the assembly having: a housing 526, the housing defining an internal cavity 534; wherein the internal cavity is isolated from an environment 535 that is external to the housing 526; a plurality of diode laser devices, 501a, 501b, 501c, 501d, 501e, for propagating a plurality of laser beams, e.g., beam 550, from a plurality of facets, e.g., facet 504, along a plurality of diode laser beam paths, e.g., path 550a, wherein the laser beams have a wavelength in the range of 400 nm to 500 nm; and wherein each laser beam has a power density of at least about 0.5 MW/cm.sup.2 at each of the facets; an optics assembly 502, the optics assembly in optical communication with each of the diode laser devices and on the laser beam paths; the optics assembly comprising collimating optics, e.g., collimating optic 560, and beam combining optics 565; the optics assembly 502 combining the plurality of diode laser beams to provide a combined laser beam 552 along a combined laser beam path 552a; wherein the plurality of diode laser devices and the optics assembly are located within the housing 526 and in the internal cavity 534, whereby the plurality of diode laser devices and the optics assembly are isolated from the external environment 535; the housing comprising a housing propagation surface 525, whereby the combined laser beam is transmitted from the housing 526 into the external environment 535 along the combined laser beam path 552a; the housing propagation surface 525 in optical communication with the optics assembly 502 and on the combined laser beam path 552a; the combined laser beam 552 upon exiting the housing propagation surface 525 characterized by beam properties, the beam properties comprising: (i) a power of at least 100 W; and, (ii) a BPP of less than 40 mm mrad; and, the internal cavity 534 being free from sources of silicon based contaminates, whereby during operation of the plurality of diode laser devices SiO.sub.2 is not produced within the internal cavity; whereby the internal cavity remains free of SiO.sub.2 build up; thereby the degradation rate of the combined beam properties is 2.3% per khrs or less.

Example 18

[0118] In embodiments of the laser assemblies of Example 17, and other

[0119] Examples, the beam properties further comprise a bandwidth of about 15 nm or less; the housing propagation surface is selected from the group consisting of a window and a fiber face; the BPP is less than about 15 mm mrad; and, the power density at the propagation surface is from about 0.5 MW/cm.sup.2 to about 1,000 MW/cm.sup.2.

Example 19

[0120] In embodiments of the laser assemblies of Example 17, and other Examples, the beam properties further comprise a bandwidth of about 15 nm or less; the power of the combined laser beam is at least about 500 W; the housing propagation surface is selected from the group consisting of a window and a fiber face; the BPP is less than about 30 mm mrad; and, the power density at the propagation surface is from about 0.5 MW/cm.sup.2 to about 1,000 MW/cm.sup.2.

Example 20

[0121] Turning to FIG. 6 there is provided a schematic of a high power, high brightness solid-state laser assembly 600, for providing a high-quality blue laser beam 650 along a laser beam path 650a over long periods of time without substantial degradation of the laser beam properties, the assembly having: a housing 626, the housing defining an internal cavity 634; wherein the internal cavity 634 defines an isolated environment; a plurality of optically active surfaces, e.g., surface 604a, surface 604b, surface 604c, surface 604d, surface 604e, wherein a blue laser beam is propagated from, transmitted into or reflected by the optically active surfaces; the plurality of optically active surfaces located within the isolated environment of the internal cavity 634 of the housing; at least one of the optically active surfaces being located on a solid-state laser device 601; wherein the laser beam has a power density of at least about 0.5 MW/cm.sup.2 at one or more of the optically active surfaces, e.g., surface 604a, surface 604b, surface 604c, surface 604d, surface 604e; and, the internal cavity 634 being free from sources of silicon based contaminates, whereby during operation of the solid-state laser device SiO.sub.2 is not produced within the internal cavity; wherein the internal cavity 634 comprises a gas comprising Oxygen; whereby during operation of the solid-state laser device CO.sub.2 is created within the internal cavity from carbon based contaminates; whereby the plurality of optically active surfaces remain free of carbon and SiO.sub.2 build up; thereby the degradation rate of a power of the blue laser beam is 2.3% per khrs or less.

[0122] Optically active surface 604e is a window providing for transmission of the laser beam 650 out of the housing and into an external environment 635.

Example 21

[0123] The laser assembly 600 of FIG. 6 and the laser assembly 500 of FIG. 5, where the solid-state laser produces a laser beam having a wavelength in the green wavelength range.

Example 21A

[0124] The green solid-solid state laser of Example 22 is an IR laser system that is doubled in a lithium niobite crystal. The system would have a laser diode, an external cavity and a lithium niobite crystal at the focal point of the external cavity, all of which would be contained within the housing.

Example 22

[0125] The laser systems and assemblies of Examples 2-21, 21A, where the laser beams have a band width of about 5 nm, about 10 nm, about 20 nm, from about 10 nm to about 30 nm, from about 5 nm to about 40 nm, about 20 nm or less, about 30 nm or less, about 15 nm or less, about 10 nm or less.

Example 23

[0126] The laser systems and assemblies of Examples 2-22, where the laser beam at, or near, the point where the beam exits the housing and propagates into the exterior environment, has powers of from about 100 W to about 100,000 W, from about 100 W to about 40,000 W, from about 100 W to about 1,000 W, about 200 W, about 250 W, about 500 W, about 1,000 W, about 10,000 W, at least about 100 W, at least about 200 W, at least about 500 W, and at least about 1,000 W.

Example 24

[0127] The laser systems and assemblies of Examples 2-23, where the laser beam has a BPP of from about 10 mm mrad to about 50 mm mrad, less than about 40 mm mrad, less than about 30 mm mrad, less than about 20 mm mrad, less than about 15 mm mrad, and less than about 10 mm mrad.

Example 25

[0128] The laser systems and assemblies of Examples 2-23, where the potential sources of silicon based contaminates, which have been removed and minimized, are siloxanes, polymerized siloxanes, linear siloxanes, cyclic siloxanes, cyclomethicones, poly-siloxanes and combinations and variations of one or more of these.

Example 26

[0129] The laser systems and assemblies of Examples 2-25, where the sources of carbon based contaminates, that are mitigated by the presences of Oxygen in the internal cavity, are solvent residues, oils, fingerprints, other sources of hydrocarbons and combinations and variations of one or more of these.

Example 27

[0130] Embodiments of solid-state, high brightness blue lasers are shown in Table 1. This table shows the power, brightness and performance that can be achieved with 2.5 Watt laser diodes in a two dimensional spectrally beam combined configuration. This table illustrates how the power and brightness of laser systems based on a building block 350 Watt module scales to the multi-kW power level using fiber combiners to launch into a process fiber.

TABLE-US-00001 TABLE 1 BPP Modules Output Power (mm-mrad) 1 350 5 2 700 13 3 1050 14 4 1400 15 5 1750 17 6 2100 19 7 2450 19 8 2800 21 9 3150 23 10 3500 24 11 3850 25 12 4200 27 13 4550 27 14 4900 28 15 5250 29 16 5600 30 17 5950 31 18 6300 32

[0131] The systems providing the beams of Table 1 have degradation rate of both beam properties of Table 1 that is from about 5% to about 1.5% per khrs or less, 2.5% per khrs or less, 2.0% per khrs or less, 1.8% per khrs or less, 1.0% per khrs or less and smaller values. The systems providing the beams of Table 1 (both beam properties) have lifetimes of from at least about 5,000 hours to about 100,000 hours, at least about 5,000 hours, at least about 10,000 hours, at least about 20,000 hours, at least about 40,000 hours from about 10,000 hours to about 50,000 hours and longer lifetimes.

Example 28

[0132] The same modules of EXAMPLE 27 may also be combined in free space which conserves brightness but makes module replacement slightly more complicated. The power and beam parameter products that can be achieved with free space combination are shown in Table 2.

TABLE-US-00002 TABLE 2 Process Fiber BPP Output Power (microns) (mm-mrad) 350 45 5 700 90 9 1050 97 10 1400 109 11 1750 122 13 2100 135 14 2450 135 14 2800 149 16 3150 163 17 3500 172 18 3850 181 19 4200 191 20 4550 195 20 4900 203 21 5250 208 22 5600 216 23 5950 219 23 6300 230 24

[0133] The systems providing the beams of Table 2 have degradation rate of both beam properties of Table 2 that is from about 5% to about 1.5% per khrs or less, 2.5% per khrs or less, 2.0% per khrs or less, 1.8% per khrs or less, 1.0% per khrs or less and smaller values. The systems providing the beams of Table 2 (both beam properties) have lifetimes of from at least about 5,000 hours to about 100,000 hours, at least about 5,000 hours, at least about 10,000 hours, at least about 20,000 hours, at least about 40,000 hours from about 10,000 hours to about 50,000 hours and longer lifetimes.

Example 29

[0134] Embodiments of solid-state, high brightness blue lasers are shown in Table 3 for systems using a higher power blue laser diode with each device being approximately 6.5 Watts. The base module is now approximately 900 Watts and these modules are combined through fiber combiners to build high power, high brightness blue laser diode systems. As shown in Table 3.

TABLE-US-00003 TABLE 3 BPP Number of Modules Output Power (mm-mrad) 1 882 5 2 1,764 13 3 2,646 14 4 3,528 15 5 4,410 17 6 5,292 19 7 6,174 19 8 7,056 21 9 7,938 23 10 8,820 24 11 9,702 25 12 10,584 27 13 11,466 27 14 12,348 28 15 13,230 29 16 14,112 30 17 14,994 31 18 15,876 32

[0135] The systems providing the beams of Table 3 have degradation rate of both beam properties that is from about 5% to about 1.5% per khrs or less, 2.5% per khrs or less, 2.0% per khrs or less, 1.8% per khrs or less, 1.0% per khrs or less and smaller values. The systems providing the beams of Table 3 (both properties) have lifetimes of from at least about 5,000 hours to about 100,000 hours, at least about 5,000 hours, at least about 10,000 hours, at least about 20,000 hours, at least about 40,000 hours from about 10,000 hours to about 50,000 hours and longer lifetimes.

Example 30

[0136] Turning to FIG. 7 is a graph of laser power vs operating times. It can be seen that the blue laser diode assembly provides an operating profile where the rate of degradation (plotted line 701) is slow. The degradation rate has a flat portion 702 at around 200 hrs to around 550 hours. After about 800 hours the rate of degradation is about 0.7% per khr. This rate of degradation shown for the time from 800 to 1,600 hours 703 will remain the same (i.e., the slope of the plotted line will not materially change) for the remainder of the lifetime of the system.

Example 31

[0137] Turning to FIG. 8 is a graph of laser power vs operating times. It can be seen that the blue laser diode assembly provides an operating profile where the rate of degradation (plotted line 801) is slow. The degradation rate has a flat portion at around 150 hrs to around 800 hours. After about 800 hours the rate of degradation is about 0.7% per khr. This rate of degradation shown for the time from 800 to 1,600 hours will remain the same (i.e., the slope of the plotted line will not materially change) for the remainder of the lifetime of the system.

Example 32

[0138] FIG. 12 is an illustration of a TO-9 Can or packaged laser diode. In packaging the laser diode the amount of Silicon based contaminates has been reduced and the package has been filled with an Oxygen rich atmosphere. The TO-9 Can 1200, has stainless steel walls 1201 that forms a housing 1205 with heat sink 1204, The TO-9 Can has a laser diode 1203 and a window 1206. The housing 1205 is filled with, e.g., contains an Oxygen rich atmosphere.

Example 33

[0139] FIGS. 13 and 14 shows how a standard TO-9 laser diode package 1200 can be arranged into a multi-laser package 1250 and 1250a by mounting the TO-9 packages into a properly machined heatsink that can hold each individual TO-9 package. The laser diodes that are mounted in the TO-9 package must be sealed with minimal Silicone contaminates, and Carbon contaminates (can be minimized), and are mitigated and managed by the Oxygen atmosphere. Once the laser diode assembly has been properly cleaned, the package 1200 is sealed with an oxygen rich environment inside the package. Each package is individually sealed to insure reliable operation.

Example 34

[0140] FIG. 15 shows a multi-die laser diode package 1501 with 20 individual laser diodes, e.g., 1502, mounted on copper bars, e.g., 1503 to create a vertical cavity emitting source. Each of the diodes are precision mounted on the copper bar, each bar is then precision mounted onto the backplane heatsink 1504. A metal mask 1505 is added to protect the diodes from back-reflections and to minimize stray or scattered light in the package and a window 1506. The package is cleaned to remove all sources of Silicone contaminates, and preferably also remove and reduce sources of Carbon contaminates. As the package is sealed, the package is filled with an oxygen rich environment to provide a means to convert any free carbon to CO2 which is harmless to the laser diodes and cannot be dissociated by the blue light. This assembly can have lifetimes of greater than 5,000 hrs, and greater than 10,000 hrs.

Example 35

[0141] FIG. 16 shows a multi-die laser diode package 1600 with 20 individual laser diodes, e.g., 1607 mounted onto the backplane heatsink 1694. The package 1600 has turning mirrors, e.g., 1606 and window 1602, through which the laser beam traveling a laser beam path, e.g., 1605 travels. The package is cleaned to remove all sources of Silicone contaminates, and preferably also remove and reduce sources of Carbon contaminates. As the package is sealed, the package is filled with an oxygen rich environment to provide a means to convert any free carbon to CO.sub.2 which is harmless to the laser diodes and cannot be dissociated by the blue light. This assembly can have lifetimes of greater than 5,000 hrs, and greater than 10,000 hrs.

Example 36

[0142] FIG. 17 shows a similar method and assembly as in FIG. 16 but now the assembly 1700 has individual sealed packages, e.g., 1701 surrounding each laser diode, e.g., 1707 and turning mirror, e.g., 1706. The packages have a window, e.g., 1702, through which laser beam along laser beam path, e.g., 1705 travels. The individual sealed packages, e.g., 1701 and the laser diodes, e.g., 1707 are mounted on a heat sink, e.g., 1704. The smaller volume surrounding each laser diode package can be cleaned easier and reduces the potential for Silicone contaminates, and preferably also remove and reduce sources of Carbon contaminates, to avoid the need for cleaning of the more complex assembly. The laser diodes and turning mirrors must be cleaned prior to sealing, to minimize the Silicone contaminates, and preferably also remove and reduce sources of Carbon contaminates. Each package, e.g., 1701 is sealed with an Oxygen rich environment to convert any residual carbon into CO.sub.2 which is harmless to the laser diode. This process results in a long lifetime for the laser diodes. This assembly can have lifetimes of greater than 5,000 hrs, and greater than 10,000 hrs.

[0143] It is noted that there is no requirement to provide or address the theory underlying the novel and groundbreaking performance or other beneficial features and properties that are the subject of, or associated with, embodiments of the present inventions. Nevertheless, various theories are provided in this specification to further advance the art in this important area, and in particular in the important area of lasers, laser processing and laser applications. These theories put forth in this specification, and unless expressly stated otherwise, in no way limit, restrict or narrow the scope of protection to be afforded the claimed inventions. These theories many not be required or practiced to utilize the present inventions. It is further understood that the present inventions may lead to new, and heretofore unknown theories to explain the operation, function and features of embodiments of the methods, articles, materials, devices and system of the present inventions; and such later developed theories shall not limit the scope of protection afforded the present inventions.

[0144] The various embodiments of lasers, diodes, arrays, modules, assemblies, activities and operations set forth in this specification may be used in the above identified fields and in various other fields. Additionally, these embodiments, for example, may be used with: existing lasers, additive manufacturing systems, operations and activities as well as other existing equipment; future lasers, additive manufacturing systems operations and activities; and such items that may be modified, in-part, based on the teachings of this specification. Further, the various embodiments set forth in this specification may be used with each other in different and various combinations. Thus, for example, the configurations provided in the various embodiments of this specification may be used with each other. For example, the components of an embodiment having A, A′ and B and the components of an embodiment having A″, C and D can be used with each other in various combination, e.g., A, C, D, and A. A″ C and D, etc., in accordance with the teaching of this Specification. The scope of protection afforded the present inventions should not be limited to a particular embodiment, configuration or arrangement that is set forth in a particular embodiment, example, or in an embodiment in a particular Figure.

[0145] The invention may be embodied in other forms than those specifically disclosed herein without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive.