DEVICE FOR ADJUSTING AN OPTICAL COMPONENT

Abstract

The present invention relates to an adjustment device for adjusting an optical component in a device for generating laser radiation, which comprises an adjuster, a coupling element and a guiding device. The coupling element is coupled to the adjuster and the guiding device and the guiding device is coupled to the optical component. The adjustment device is capable of changing the position of the optical component, wherein two of the elements (4, 5, 6) of the adjustment device (4) are coupled by magnetic power transmission. Arrangements of this kind make possible to provide laser beam sources which stand out by a particular long lifetime, in particular in the field of high-energy radiation.

Claims

1. An adjustment device for adjusting an optical component in a device for generating laser radiation, comprising an adjuster, a coupling element a guiding device, wherein the coupling element is coupled to the adjuster and the guiding device, wherein the guiding device is coupled to the optical component, wherein the adjustment device is capable of changing the position of the optical component, wherein two of the elements of the adjustment device are coupled by magnetic power transmission.

2. The adjustment device for adjusting an optical component in a device for generating laser radiation according to claim 1, characterized in that the device for generating laser radiation comprises a sealed chamber, wherein the adjuster arranged outside the chamber and the guiding device is arranged inside the chamber and/or wherein the two of the elements of the adjustment device are coupled by power transmission through a wall of the chamber.

3. The adjustment device for adjusting an optical component in a device for generating laser radiation according to claim 1, characterized in that the adjustment device comprises an intermediate element, wherein the power transmission from the adjuster to the optical component is via the intermediate element.

4-20. (canceled)

21. The adjustment device for adjusting an optical component in a device for generating laser radiation according to claim 2, characterized in that the sealed chamber comprises an opening, wherein an element of the adjustment device is guided through the opening of the chamber and/or the adjustment device comprises a seal which seals the space between the element guided through the opening of the chamber and the edge of the opening.

22. The adjustment device for adjusting an optical component in a device for generating laser radiation according to claim 21, characterized in that the element of the adjustment device guided through the opening and the coupling element have contact surfaces by means of which the element of the adjustment device guided through the opening and the coupling element are connected.

23. The adjustment device for adjusting an optical component in a device for generating laser radiation according to claim 22, characterized in that the element of the adjustment device guided through the opening is connected in a laterally movable manner to the coupling element by means of the contact surfaces.

24. The adjustment device for adjusting an optical component in a device for generating laser radiation according to claim 23, characterized in that the diameter of the contact surfaces of the element of the adjustment device guided through the opening and that of the coupling element are different.

25. An adjustment device for adjusting an optical component in a device for generating laser radiation according to claim 1, comprising a first adjustment device, configured to adjust the optical component in a first direction; and a second adjustment device, configured to adjust the optical component in a second direction.

26. A device for generating laser radiation comprising a resonator, an optical assembly, characterized in that it comprises an adjustment device according to claim 1.

27. A method for adjusting an optical component in a device for generating laser radiation, wherein the power is transmitted magnetically between two elements of an adjustment device according to claim 1.

28. The method for adjusting an optical component in a device for generating laser radiation according to claim 27, characterized in that the optical element is adjusted relative to a resonator from a first position to a second position.

29. The method for adjusting an optical component in a device for generating laser radiation according to claim 28, characterized in that by adjusting the optical component, the target surface of the laser radiation on the optical element is changed, wherein the direction of the beam path of the laser radiation coming from the optical component remains unchanged by the adjustment of the optical component.

Description

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

[0035] Embodiments of the device according to the invention and the method according to the invention are shown in a schematically simplified manner in the drawings and will be discussed in more detail in the following description.

[0036] FIG. 1a shows a top view of the adjustment device in a device for generating laser radiation with two adjustment devices for adjusting the optical elements

[0037] FIG. 1b shows a side view of the adjustment device in a device for generating laser radiation with two adjustment devices for adjusting the optical elements

[0038] FIG. 2 shows a side view of the adjustment device in a device for generating laser radiation with magnetic power transmission through an opening in the chamber

[0039] FIG. 3 shows a side view of the adjustment device with magnetic power transmission through an opening in the chamber

[0040] FIG. 4 shows a side view of the adjustment device with intermediate element

[0041] FIG. 5 shows a view of the adjustment device with intermediate element

[0042] FIG. 6 shows a side view of the adjustment device with a coupling element with a ball-shaped surface

[0043] FIG. 7 shows a side view of the adjustment device for transmitting a rotational movement through the wall of the chamber

[0044] FIG. 8a shows a laser resonator with an internal adjustable optical assembly

[0045] FIG. 8b shows an adjustable optical assembly

DETAILED DESCRIPTION

[0046] The device for generating laser radiation 1 in FIG. 1a and FIG. 1b comprises a resonator 2 generating a primary laser radiation and a frequency conversion device 15. The optical component 3 for deflecting the laser radiation is permanently connected to the adjustment device 4 by means of an adapter 16 and guided in the guiding device 7 of the adjustment device 4. The intermediate element 8 is arranged at the wall 14 of the chamber 9 in a manner adjustable parallel to the surface of the wall 14. The adjuster 5 is connected to the coupling element 6 outside the chamber 9. The power is transmitted magnetically between the coupling element 6 and the intermediate element 8. In this embodiment, the coupling element 6 comprises a magnetic material and is configured as a permanent magnet and the intermediate element 8 consists at least partially of a ferromagnetic material. The coupling element 6 and the intermediate element 8 are coupled by the magnetic attraction forces through the wall 14. Alternatively, also the intermediate element 8 can be configured as a magnet and the coupling element 6 can consist of the ferromagnetic material. Alternatively, it is also possible to use electromagnets. The adjustment device can be mechanical or motor-driven.

[0047] Furthermore, the adapter 16 is connected permanently to a second guiding device 7′. A second adjuster 5′ is connected to a second coupling element 6′ outside the chamber 9. Also in this case the power is transmitted magnetically between the second coupling element 6′ and a second intermediate element 8′. In the second adjustment device 4′, the second coupling element 6′ is configured as a permanent magnet and the second intermediate element 8′ in turn consists at least partially of a ferromagnetic material. The second coupling element 6′ is guided through an opening of the chamber 9. The gap between the chamber 9 and the second coupling element 6′ is sealed by means of a seal 13. The second coupling element 6′ is movably arranged at the second intermediate element 8′. When adjusting the optical components 3 by means of the first adjustment device 4, the second coupling element 6′ slides over the surface of the second intermediate element 8′, but still remains coupled thereto by the magnetic forces. Alternatively, also the use of electromagnets is possible. The adjustment device can be mechanical or motor-driven.

[0048] The optical component 3 can be a mirror, prism, a lens, an optically parametric oscillator (OPO) or a further frequency conversion device 15. A plurality of optical components 3 can be combined in an optical assembly and can be adjusted as a whole by means of the adjuster 5. The entire optical assembly is adjusted, an adjustment of individual optical components 3 as known in the prior art is not necessary. Therefore, the design and operation of the presented adjustment device 4 according to the invention are more cost-efficient, compacter and can be handled more easily. Moreover, fewer components are present in the chamber 9, which can discharge substances which can then in turn deposit on the optical components 3. In interaction with the laser radiation, in particular laser radiation in the UV range, these substances can also lead to a degradation of the optical component 3. This in the end leads to a reduction in the efficiency of the laser system.

[0049] For adjusting the optical component 3, the coupling element 6 is adjusted by an amount relative to the resonator 2 by means of the adjuster 5. In this embodiment, the adjustment is realized in the vertical direction. The intermediate element 8 is adjusted horizontally by the magnetic power transmission by the same amount as the optical component 3 is adjusted horizontally by the guiding device 7. The position of the reflected laser radiation A is not changed by the displacement, but the position of the laser spot X on the optical component 3 is changed. Thus, any desired undamaged or previously unused position on the optical component 3 can be selected as the target area of the laser radiation and positioned in the beam path of the resonator 2.

[0050] In FIG. 2 the adjustment device 4 is connected to the optical component 3 to be adjusted by means of an opening 10 in the chamber 9. The opening 10 comprises seals 13 for preventing the interior of the chamber 9 from dust and other contaminants from outside, which can decrease or increase the lifetime of the optical components 3 in the chamber 9. The primary laser radiation A generated by the resonator 2 is directed to the optical component 3 to be adjusted by the frequency conversion device 15. The optical component 3 is guided in the guiding device 7 which is magnetically connected to the coupling element 6. The coupling is realized by the coupling element that is configured as a magnet and by ferromagnetic material at the guiding device.

[0051] The coupling element 6 is adjusted by means of the adjuster 5. By the magnetic coupling of the coupling element 6 and the guiding device 7, at the same time the optical component 3 is adjusted. The sealed chamber 9 can be evacuated or flushed in order to minimize the number of dust particles and degassing products in the air. The seals 13 arranged in the opening 10 of the chamber 9 seal the spaces between the wall of the chamber 9 and the coupling element 6 guided through the opening 10 from external air.

[0052] A detailed view of the adjustment device 4 according to the invention is shown in FIG. 3. The adjuster 5 is connected to the coupling element 6 which is magnetically connected to the guiding device 7 through a sealed opening 10 in the chamber 9. The optical component 3 to be adjusted is connected to the guiding device 7. In this case, an element of the guiding device 7 is configured as a magnet, while the coupling element 6 consists of a ferromagnetic material.

[0053] The coupling element 6 can be adjusted by means of a screw thread. In the simplest case, a manual adjustment is then possible. But also a motor-driven adjustment is conceivable. Then, the adjustment can also be controlled by a computer program and thus can be automated when the power of the laser system falls below a predetermined value. By the adjustor 5, the coupling element 6 is adjusted by an amount. The optical component 3 is adjusted by the same amount by the magnetic coupling of coupling element 6 and guiding device 7. In an alternative embodiment an optical component 3 is adjustable by means of two adjustment devices. In this manner, adjustment can be realized in two directions independently of one another and, for example, the entire surface of an optical component can be screened. The lifetime of the optical component 3 is thus increased considerably.

[0054] FIG. 4 shows an adjustment device 4 according to the invention with an intermediate element 8. The adjuster 5 is connected to the coupling element 6 which is magnetically coupled to the intermediate element 8 through a sealed opening 10 in the chamber 9. The intermediate element 8 is in turn magnetically coupled to the guiding device 7. This connection can alternatively also be permanent. In this embodiment of the invention, both the intermediate element 8 and the coupling element 6 are configured as magnets. The optical component 3 to be adjusted is guided in the guiding device 7. If the movement direction of the coupling element 6 and that of the optical component 3 guided in the guiding device 7 are not parallel, the intermediate element 8 allows for a certain play in all spatial axes in order to compensate for the offset of the two movement directions. Furthermore, fine-adjustment movements can be compensated for by the intermediate element 8. For example, if the coupling element 6 with the adjuster 5 is distorted by a small angle in the clockwise or counter-clockwise direction relative to the guiding device 7, the coupling element 6 moves laterally when the optical component 3 is adjusted in the vertical. The intermediate element 8 is thus adjusted parallel to the guiding device 7. By the magnetic coupling between coupling element 6, intermediate element 8 and guiding device 7, an adjustment in the vertical is guaranteed. This is the case, e.g., if the adjustment device 4 is retrofitted in an already existing device for generating laser radiation 1.

[0055] The mode of operation of the intermediate element 8 is shown more clearly in FIG. 5. The adjuster 5 is connected to the coupling element 6 which is magnetically coupled to the intermediate element 8. The intermediate element 8 is in turn coupled magnetically to the guiding device 7. The optical component 3 to be adjusted is guided in the guiding device 7. If the movement direction of the coupling element 6 and that of the optical component 3 guided in the guiding device 7 are not parallel, the non-permanent magnetic coupling between coupling element 6, intermediate element 8 and guide device 7 leads to a play which is compensated for by the intermediate element 8. When moving the optical component 3 in the vertical direction, the coupling element 6 moves to the side and slides on the contact surfaces 11, 12 of the coupling element 6 and the intermediate element 8. The intermediate element 8 itself is adjusted parallel to the optical component 3.

[0056] The magnetic coupling between coupling element 6, intermediate element 8 and guiding device 7 can be realized in that one of these three components 6, 7, 8 is a permanent magnet and the other two components 6, 7, 8 consist of a ferromagnetic material. In this connection it is irrelevant which of the three components 6, 7, 8 is the magnet. What is important is only a magnetic coupling of these three components 6, 7, 8. In this embodiment, the individual elements 5, 6, 8, 7 of the adjustment device 4 are coupled in that the coupling element 6 comprises a permanent magnet. By the magnetic field, the coupling element 6 is coupled to the intermediate element 8 consisting of a ferromagnetic material. By the magnetic field, at the same time the ferromagnetic material of the intermediate element 8 is magnetized. The intermediate element 8 magnetized in this manner in turn couples to the guiding device 7 by magnetic forces.

[0057] FIG. 6 shows an adjustment device 4 having a construction that is analog to that of the adjustment device of FIG. 4. The contact surface 17 of the coupling element 6 to the intermediate element 8 is ball-shaped in this embodiment. Thus, friction is reduced when the coupling element 6 slides across the contact surface of the intermediate element 8. Furthermore, the ball-shaped contact surface 17 of the coupling element 6 can compensate for rotational movements or also lateral movements of the intermediate element 8 and/or the adjustment device 4, which would lead to a tilting motion between coupling element 6 and intermediate element 8. Such a tilting motion can occur, e.g., when fine-adjusting the optical components 3. The ball-shaped surface 17 can also be arranged at the intermediate element 8, for example in that the intermediate element 8 is formed as a sphere. In a further alternative embodiment, the sliding movement between intermediate element 8 and coupling element 6 can also be omitted, because due to the possibility of tilting, slight lateral movements can also be compensated for without the contact between the coupling element 6 and the intermediate element 8 being interrupted.

[0058] The device for generating laser radiation 1 of FIG. 7 comprises a resonator 2, which is not shown in the drawing and generates a primary laser radiation, and a frequency conversion device 15. The optical component 3 for deflecting the laser radiation is permanently connected to the adjustment device 4 by means of the guiding device 7 and guided therein. The intermediate element 8 is arranged at the wall 14 of the chamber 9 towards the surface of the wall 14, but is not permanently but adjustably connected to the wall 14. The adjuster 5 is connected to the coupling element 6 outside the chamber 9. The adjuster transmits a rotational movement to the coupling element. The power is transmitted magnetically between the coupling element 6 and the intermediate element 8, so that the intermediate element also makes a rotational movement. A linear adjuster 19 converts the rotational movement into a linear movement of the guiding element. The linear adjuster can comprise, e.g., a threaded rod. By the rotation of said threaded rod, a helical groove is moved linearly. In this embodiment, the coupling element 6 comprises a magnetic material and is configured as a permanent magnet, and the intermediate element 8 consists at least partly of a ferromagnetic material. The coupling element 6 and the intermediate element 8 are coupled by the magnetic attraction forces through the wall 14.

[0059] FIG. 8a shows a laser system in which a pump beam 100 is focused through a lens 101 onto the laser medium 103. The focused pump beam 100 passes through a resonator mirror 102 that is transparent to the wavelength of the pump beam 100 into the resonator of the laser system. In the laser medium 103, the coherent laser radiation 110 is generated by the pump radiation 100 preferably in the wavelength range of the UV light. The coherent laser beam 110 is guided by the laser medium 103 first through the quality switch (Q switch) 104. Through a mirror 107 that is transparent to selected wavelengths, the laser beam 110 reaches the frequency tripler 106 and the frequency doubler 105. From the second resonator mirror 102, the beam is reflected back into the beam path and divided at the mirror 107 that is transparent to selected wavelengths. Part of the laser beam penetrates the mirror 107 that is transparent to selected wavelengths and remains in the resonator. The laser beam converted by non-linear processes is separated by the mirror 107 that is transparent to selected wavelengths and decoupled from the resonator. A further deflection is made by the mirror 108.

[0060] In this embodiment, the adjustable optical assembly 109 comprises the frequency tripler 106, the separator mirror 107 that is transparent to selected wavelengths, and the mirror 108 (see FIG. 8b). This adjustable optical assembly 109 is arranged on a support element. By adjusting the support element, each individual element of the adjustable optical assembly 109 is moved by exactly the same distance as each other element of the adjustable optical assembly 109. In that the adjustable optical assembly 109 is adjusted as a whole, the laser beam 110 emanating from the resonator remains in the same position independent of the adjustment of the optical assembly 109. A crystal for generating the second harmonic can also be added to the assembly 109 as an embodiment.

LIST OF REFERENCE SIGNS

[0061] 1 device for generating laser radiation [0062] 2 resonator [0063] 3 optical assembly [0064] 4 adjustment device [0065] 5, 5′ adjuster [0066] 6,6′ coupling element [0067] 7 guiding device [0068] 8 intermediate element [0069] 9 chamber [0070] 10 opening [0071] 11, 12 contact surfaces [0072] 13 seal [0073] 14 wall [0074] 15 frequency conversion device [0075] 16 adapter [0076] 17 ball-shaped surface [0077] 18 connection piece [0078] 19 linear adjustment [0079] 20 mirror [0080] 100 pump beam [0081] 101 lens [0082] 102 resonator mirror [0083] 103 laser medium [0084] 104 Q switch [0085] 105 frequency doubler [0086] 106 frequency tripler [0087] 107 separator mirror [0088] 108 mirror [0089] 109 adjustable optical assembly [0090] 110 laser beam [0091] A laser beam path before movement of the optical assembly [0092] X laser spot