VERTICAL EXTERNAL CAVITY SURFACE EMITTING LASER (VECSEL) ARRAY

Abstract

An electrical pumping vertical external-cavity surface-emitting laser (EP-VECSEL) device. The device includes a first reflective element and an active region comprising a plurality of emitters, disposed on the first reflective element configured to accept an electrical current at multiple emitters on the active region such that the multiple emitters produce a plurality of lasers. The multiple emitters may be configured to form a desired Hermite Gaussian (HG) mode shape. The device includes a second reflective element disposed on the active region. The device further includes an array output coupler disposed optically in line with the second reflective element such that the plurality of lasers are directed into the array output coupler.

Claims

1. A vertical external-cavity surface-emitting laser (VECSEL) device (100) comprising: a. a first reflective element (130); b. an active region (120) comprising a plurality of emitters, disposed on the first reflective element (130) and configured to accept a signal at two or more emitters on the active region (120) such that the two or more emitters produce a plurality of lasers, each emitter of the plurality of emitters comprising: i. a heat spreader component (121); ii. a VECSEL (122) disposed on the heat spreader component (121); iii. an intracavity heat spreader component (123) disposed at least partially within a cavity disposed in the VECSEL (122); iv. a frequency selection element (124) disposed parallel to and optically in line with the intracavity heat spreader component (123); v. one or more lenses (125) disposed parallel to and optically in line with the frequency selection element (124); and vi. an emitter output coupler (126) disposed parallel to and optically in line with the one or more lenses (125); wherein the two or more emitters are configured to form a desired Hermite Gaussian (HG) mode shape; c. a second reflective element (140) disposed on the active region (120), configured to reflect the plurality of lasers; and d. an array output coupler (160) disposed optically in line with the second reflective element (140) such that the plurality of lasers are reflected from the second reflective element (140) and directed into the array output coupler (160).

2. The VECSEL device (100) of claim 1 further comprising a piezoelectric element operatively coupled to the device (100), configured to move the emitter output coupler (126) such that a shape of the laser emitted by the emitter is changed.

3. The VECSEL device (100) of claim 2, wherein the piezoelectric element is operatively coupled to the cavity, the heat spreader component (121), the output coupler, or a combination thereof.

4. The VECSEL device (100) of claim 1, wherein the signal comprises an electrical signal, an optical signal, or a combination thereof.

5. The VECSEL device (100) of claim 1, wherein the heat spreader component (121) comprises a chemical vapor deposition (CVD) diamond, a single-crystal diamond, silicon carbide, copper, aluminum, or a combination thereof.

6. The VECSEL device (100) of claim 1, wherein the frequency selection element (124) comprises an etalon, a birefringent filter, a diffraction grating, a dichroic mirror, or a combination thereof.

7. The VECSEL device (100) of claim 1 further comprising a bottom contact (110) operatively coupled to the first reflective element (130), a top contact (150) disposed on the second reflective element (140), or a combination thereof; wherein the bottom contact (110), the top contact (150), or a combination thereof are configured for thermal transmission, electrical transmission, optical transmission, or a combination thereof; wherein the bottom contact (110), the top contact (150), or a combination thereof are configured to shape or transmit the plurality of lasers.

8. The VECSEL device (100) of claim 1, wherein the first reflective element (130) comprises a distributed Bragg reflector (DBR), a mirror, a dielectric coating, a metal coating, or a combination thereof; wherein the second reflective element (140) comprises a distributed Bragg reflector (DBR), a mirror, a dielectric coating, a metal coating, or a combination thereof.

9. A vertical external-cavity surface-emitting laser (VECSEL) device (100) comprising: a. an active region (120) comprising a plurality of emitters, configured to accept a signal at two or more emitters of the plurality of emitters such that the two or more emitters produce a plurality of lasers, each emitter of the plurality of emitters comprising: i. a heat spreader component (121); ii. a VECSEL (122) disposed on the heat spreader component (121); iii. an intracavity heat spreader component (123) disposed at least partially within a cavity disposed in the VECSEL (122); iv. a frequency selection element (124) disposed parallel to and optically in line with the intracavity heat spreader component (123); v. one or more lenses (125) disposed parallel to and optically in line with the frequency selection element (124); and vi. an emitter output coupler (126) disposed parallel to and optically in line with the one or more lenses (125); wherein the two or more emitters are configured to form a desired Hermite Gaussian (HG) mode shape; and b. an array output coupler (160) disposed optically in line with the active region (120) such that the plurality of lasers are directed into the array output coupler (160).

10. The VECSEL device (100) of claim 9 further comprising a piezoelectric element operatively coupled to the device (100), configured to move the emitter output coupler (126) such that a shape of the laser emitted by the emitter is changed.

11. The VECSEL device (100) of claim 10, wherein the piezoelectric element is operatively coupled to the cavity, the heat spreader component (121), the output coupler, or a combination thereof.

12. The VECSEL device (100) of claim 9, wherein the signal comprises an electrical signal, an optical signal, or a combination thereof.

13. The VECSEL device (100) of claim 9, wherein the heat spreader component (121) comprises a chemical vapor deposition (CVD) diamond, a single-crystal diamond, silicon carbide, copper, aluminum, or a combination thereof.

14. The VECSEL device (100) of claim 9, wherein the frequency selection element (124) comprises an etalon, a birefringent filter, a diffraction grating, a dichroic mirror, or a combination thereof.

15. The VECSEL device (100) of claim 9, wherein the first reflective element (130) comprises a distributed Bragg reflector (DBR), a mirror, a dielectric coating, a metal coating, or a combination thereof; wherein the second reflective element (140) comprises a distributed Bragg reflector (DBR), a mirror, a dielectric coating, a metal coating, or a combination thereof.

16. A vertical external-cavity surface-emitting laser (VECSEL) system comprising: a. a power supply (200); b. a VECSEL device (100) comprising: i. a first reflective element (130); ii. an active region (120) comprising a plurality of emitters, disposed on the first reflective element (130) configured to accept a signal at two or more emitters on the active region (120) such that the two or more emitters produce a plurality of lasers; wherein the two or more emitters are configured to form a desired Hermite Gaussian (HG) mode shape; iii. a second reflective element (140) disposed on the active region (120), configured to reflect the plurality of lasers; and iv. an array output coupler (160) disposed optically in line with the second reflective element (140) such that the plurality of lasers are reflected from the second reflective element (140) and directed into the array output coupler (160); c. a beam intrusion monitor (300) optically in line with the VECSEL device (100); d. a targeting and relay system (400) operatively coupled to the beam intrusion monitor (300); e. a photovoltaic (PV) array (500) operatively coupled to the targeting and relay system (400); and f. a battery (600) operatively coupled to the PV array (500).

17. The system of claim 16, wherein each emitter of the plurality of emitters comprise: a. a heat spreader component (121); b. a VECSEL (122) disposed on the heat spreader component (121); c. an intracavity heat spreader component (123) disposed at least partially within a cavity disposed in the VECSEL (122); d. a frequency selection element (124) disposed parallel to and optically in line with the intracavity heat spreader component (123); e. one or more lenses (125) disposed parallel to and optically in line with the frequency selection element (124); and f. an emitter output coupler (126) disposed parallel to and optically in line with the one or more lenses (125).

18. The system of claim 17 further comprising a piezoelectric element operatively coupled to the device (100), configured to move the emitter output coupler (126) such that a shape of the laser emitted by the emitter is changed.

19. The system of claim 16, wherein the signal comprises an electrical signal, an optical signal, or a combination thereof.

20. The system of claim 16, wherein the VECSEL device (100) further comprises a bottom contact (110) operatively coupled to the first reflective element (130), a top contact (150) disposed on the second reflective element (140), or a combination thereof; wherein the bottom contact (110), the top contact (150), or a combination thereof are configured for thermal transmission, electrical transmission, optical transmission, or a combination thereof; wherein the bottom contact (110), the top contact (150), or a combination thereof are configured to shape or transmit the plurality of lasers.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

[0013] The features and advantages of the present invention will become apparent from a consideration of the following detailed description presented in connection with the accompanying drawings in which:

[0014] FIG. 1 shows a simple prior electrical pumped VECSEL design.

[0015] FIG. 2 shows a design of an electrical pumping scheme for higher-order HG modes from a VECSEL.

[0016] FIG. 3 shows an array of individual VECSEL lasers. Each dot on the image can emit a laser beam of any designed HG order, including a diffraction-limited HG.sub.0,0 Gaussian beam.

[0017] FIG. 4 shows a schematic of each pixel and possible elements to be included.

[0018] FIG. 5 shows a scheme in which the VECSEL laser array can be implemented for free space beam transfer.

[0019] FIG. 6 shows a plurality of emitters in-line with a common output coupler.

[0020] FIG. 7 shows a plurality of emitters each having its own individual laser cavity. The beams from the plurality of emitters are then combined.

[0021] FIG. 8A shows a first configuration of the VECSEL device of the present invention.

[0022] FIG. 8B shows a second configuration of the VECSEL device of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0023] Following is a list of elements corresponding to a particular element referred to herein: [0024] 100 device [0025] 110 bottom contact [0026] 120 active region [0027] 121 CVD diamond [0028] 122 EP-VECSEL [0029] 123 intracavity CVD [0030] 124 etalon [0031] 125 microlens array [0032] 126 emitter output coupler [0033] 130 first DBR [0034] 140 second DBR [0035] 150 top contact [0036] 155 anti-reflective coating [0037] 160 array output coupler [0038] 200 power supply [0039] 300 beam intrusion monitor [0040] 400 targeting and relay system [0041] 500 PV array [0042] 600 battery [0043] 700 second beam intrusion monitor

[0044] The term Hermite-Gaussian (HG) mode shape is defined herein as a shape of a beam of electromagnetic radiation with high monochromaticity whose amplitude envelope in the transverse plane is given by a Gaussian function determined by a system of mutually orthogonal functions.

[0045] The term etalon is defined herein as an optical device containing parallel mirrors, used as a narrow band filter, often in laser design.

[0046] The term astigmatic mode converter is defined herein as a mode converter that transforms a Hermite-gaussian mode of arbitrarily high order to a Laguerre-gaussian mode and vice versa.

[0047] The terms N-type distributed Bragg reflector (DBR) and P-type DBR are defined herein as reflectors used in waveguides, such as optical fibers, formed from multiple layers of alternating materials with different refractive index, or by periodic variation of some characteristic (such as height) of a dielectric waveguide, resulting in periodic variation in the effective refractive index in the guide. An N-type DBR may be doped such that the DBR comprises excess electrons. A P-type DBR may be doped such that the DBR comprises excess holes.

[0048] The term chemical vapor deposition (CVD) diamond refers to a diamond generated by a vacuum deposition method, wherein a wafer (substrate) is exposed to one or more volatile precursors, which react and/or decompose on the substrate surface to produce the desired deposit (the diamond).

[0049] The term VECSEL (Vertical External Cavity Surface Emitting Laser) is referred to herein as a semiconductor laser with an external laser cavity, where the laser light propagates perpendicular to the semiconductor wafer surface.

[0050] The term electrical pumping is referred to herein as passing an electric current through a gain medium to excite the atoms or molecules.

[0051] The present invention features a vertical external-cavity surface-emitting laser (VECSEL) device (100). The device (100) may comprise a first reflective element (130). The device (100) may further comprise an active region (120) comprising a plurality of emitters, disposed on the first reflective element (130) and configured to accept a signal at two or more emitters on the active region (120) such that the two or more emitters produce a plurality of lasers. Each emitter may comprise a heat spreader component (121). Each emitter may further comprise a VECSEL (122) disposed on the heat spreader component (121). Each emitter may further comprise an intracavity heat spreader component (123) disposed at least partially within a cavity disposed in the VECSEL (122). Each emitter may further comprise a frequency selection element (124) disposed parallel to and optically in line with the intracavity heat spreader component (123). Each emitter may further comprise one or more lenses (125) disposed parallel to and optically in line with the frequency selection element (124). Each emitter may further comprise an emitter output coupler (126) disposed parallel to and optically in line with the one or more lenses (125). The two or more emitters may be configured to form a desired Hermite Gaussian (HG) mode shape. The device (100) may further comprise a second reflective element (140) disposed on the active region (120), configured to reflect the plurality of lasers. The device (100) may further comprise an array output coupler (160) disposed optically in line with the second reflective element (140) such that the plurality of lasers are reflected from the second reflective element (140) and directed into the array output coupler (160).

[0052] In some embodiments, the device (100) may further comprise a piezoelectric element operatively coupled to the device (100), configured to move the emitter output coupler (126) such that a shape of the laser emitted by the emitter is changed. In some embodiments, the piezoelectric element may be operatively coupled to the cavity, the heat spreader component (121), the output coupler, any other component of the device (100), or a combination thereof. In some embodiments, the signal may comprise an electrical signal, an optical signal, or a combination thereof. In some embodiments, the heat spreader component (121) may comprise a chemical vapor deposition (CVD) diamond, a single-crystal diamond, silicon carbide, copper, aluminum, any other material capable of heat distribution, or a combination thereof. In some embodiments, the intracavity heat spreader component (121) may comprise a chemical vapor deposition (CVD) diamond, a single-crystal diamond, silicon carbide, copper, aluminum, any other material capable of heat distribution, or a combination thereof.

[0053] In some embodiments, the frequency selection element (124) may comprise an etalon, a birefringent filter, a diffraction grating, a dichroic mirror, any component capable of frequency selection, or a combination thereof. In some embodiments, the device (100) may further comprise a bottom contact (110) operatively coupled to the first reflective element (130), a top contact (150) disposed on the second reflective element (140), or a combination thereof. In some embodiments, the bottom contact (110), the top contact (150), or a combination thereof may be configured for thermal transmission, electrical transmission, optical transmission, or a combination thereof. In some embodiments, the bottom contact (110), the top contact (150), or a combination thereof may be configured to shape or transmit the plurality of lasers. In some embodiments, the first reflective element (130) may comprise a distributed Bragg reflector (DBR), a mirror, a dielectric coating, a metal coating, any other reflective material, or a combination thereof. The second reflective element (140) may comprise a distributed Bragg reflector (DBR), a mirror, a dielectric coating, a metal coating, any other reflective material, or a combination thereof.

[0054] The present invention features a vertical external-cavity surface-emitting laser (VECSEL) device (100). The device (100) may comprise an active region (120) comprising a plurality of emitters, configured to accept a signal at two or more emitters of the plurality of emitters such that the two or more emitters produce a plurality of lasers. Each emitter may comprise a heat spreader component (121). Each emitter may further comprise a VECSEL (122) disposed on the heat spreader component (121). Each emitter may further comprise an intracavity heat spreader component (123) disposed at least partially within a cavity disposed in the VECSEL (122). Each emitter may further comprise a frequency selection element (124) disposed parallel to and optically in line with the intracavity heat spreader component (123). Each emitter may further comprise one or more lenses (125) disposed parallel to and optically in line with the frequency selection element (124). Each emitter may further comprise an emitter output coupler (126) disposed parallel to and optically in line with the one or more lenses (125). The two or more emitters may be configured to form a desired Hermite Gaussian (HG) mode shape. The device (100) may further comprise an array output coupler (160) disposed optically in line with the active region (120) such that the plurality of lasers are directed into the array output coupler (160).

[0055] In some embodiments, the device (100) may further comprise a piezoelectric element operatively coupled to the device (100), configured to move the emitter output coupler (126) such that a shape of the laser emitted by the emitter is changed. In some embodiments, the piezoelectric element may be operatively coupled to the cavity, the heat spreader component (121), the output coupler, any other component of the device (100), or a combination thereof. In some embodiments, the signal may comprise an electrical signal, an optical signal, or a combination thereof. In some embodiments, the heat spreader component (121) may comprise a chemical vapor deposition (CVD) diamond, a single-crystal diamond, silicon carbide, copper, aluminum, any other material capable of heat distribution, or a combination thereof. In some embodiments, the intracavity heat spreader component (121) may comprise a chemical vapor deposition (CVD) diamond, a single-crystal diamond, silicon carbide, copper, aluminum, any other material capable of heat distribution, or a combination thereof.

[0056] In some embodiments, the frequency selection element (124) may comprise an etalon, a birefringent filter, a diffraction grating, a dichroic mirror, any component capable of frequency selection, or a combination thereof. In some embodiments, the first reflective element (130) may comprise a distributed Bragg reflector (DBR), a mirror, a dielectric coating, a metal coating, any other reflective material, or a combination thereof. In some embodiments, the second reflective element (140) may comprise a distributed Bragg reflector (DBR), a mirror, a dielectric coating, a metal coating, any other reflective material, or a combination thereof.

[0057] The present invention features a vertical external-cavity surface-emitting laser (VECSEL) system. The system may comprise a power supply (200). The system may further comprise a VECSEL device (100). The device (100) may comprise a first reflective element (130). The device (100) may further comprise an active region (120) comprising a plurality of emitters, disposed on the first reflective element (130) configured to accept a signal at two or more emitters on the active region (120) such that the two or more emitters produce a plurality of lasers. The two or more emitters may be configured to form a desired Hermite Gaussian (HG) mode shape. The device (100) may further comprise a second reflective element (140) disposed on the active region (120), configured to reflect the plurality of lasers. The device (100) may further comprise an array output coupler (160) disposed optically in line with the second reflective element (140) such that the plurality of lasers are reflected from the second reflective element (140) and directed into the array output coupler (160). The system may further comprise a beam intrusion monitor (300) optically in line with the VECSEL device (100). The system may further comprise a targeting and relay system (400) operatively coupled to the beam intrusion monitor (300). The system may further comprise a photovoltaic (PV) array (500) operatively coupled to the targeting and relay system (400). The system may further comprise a battery (600) operatively coupled to the PV array (500).

[0058] In some embodiments, each emitter of the plurality of emitters may comprise a heat spreader component (121). Each emitter may further comprise a VECSEL (122) disposed on the heat spreader component (121). Each emitter may further comprise an intracavity heat spreader component (123) disposed at least partially within a cavity disposed in the VECSEL (122). Each emitter may further comprise a frequency selection element (124) disposed parallel to and optically in line with the intracavity heat spreader component (123). Each emitter may further comprise one or more lenses (125) disposed parallel to and optically in line with the frequency selection element (124). Each emitter may further comprise an emitter output coupler (126) disposed parallel to and optically in line with the one or more lenses (125). In some embodiments, the signal may comprise an electrical signal, an optical signal, or a combination thereof. In some embodiments, the system may further comprise a piezoelectric element operatively coupled to the device (100), configured to move the emitter output coupler (126) such that a shape of the laser emitted by the emitter is changed. In some embodiments, the VECSEL device (100) may further comprise a bottom contact (110) operatively coupled to the first reflective element (130), a top contact (150) disposed on the second reflective element (140), or a combination thereof. The bottom contact (110), the top contact (150), or a combination thereof may be configured for thermal transmission, electrical transmission, optical transmission, or a combination thereof. The bottom contact (110), the top contact (150), or a combination thereof may be configured to shape or transmit the plurality of lasers.

[0059] In some embodiments, the active region (120) may be directly coupled to the first reflective element (130). In some embodiments, the device (100) may comprise an air gap between the active region (120) and the first reflective element (130). In some embodiments, the first reflective element (130) may be coupled to the piezoelectric element. In some embodiments, the VECSEL device (100) may comprise one or more heat spreader components. In some embodiments, the active region (120) may comprise a first heat spreader component operatively coupled to a first end of the active region and a second heat spreader component operatively coupled to a second end of the active region. In some embodiments, the device (100) may comprise an air gap between the first reflective element (130) and the first heat spreader component In some embodiments, the VECSEL device (100) may comprise a heat spreader component operatively coupled to the bottom contact (110).

[0060] In some embodiments, the top contact (150), the bottom contact (110), or a combination thereof may comprise a plurality of wire structures configured to define a desired shape of the lasers directed through the top contact (150), the bottom contact (110), or the combination thereof. In some embodiments, the top contact (150), the bottom contact (110), or a combination thereof may be at least partially transparent such that the plurality of lasers can be transmitted through the bottom contact (110), the top contact (150), or the combination thereof. In some embodiments, the top contact (150), the bottom contact (110) or a combination thereof may comprise one or more filters configured to modulate the top contact (150), the bottom contact (110), or the combination thereof.

[0061] Referring now to FIG. 2, the present invention features an electrical pumping vertical external-cavity surface-emitting laser (EP-VECSEL) device (100). In some embodiments, the device (100) may comprise a bottom contact (110), a first distributed Bragg reflector (DBR) (130) disposed on the bottom contact (110), and an active region (120) comprising a plurality of emitters, disposed on the first DBR (130) configured to accept an electrical current at two or more emitters on the active region (120) such that the two or more emitters produce a plurality of lasers. The two or more emitters may be configured to form a desired Hermite Gaussian (HG) mode shape. The device (100) may further comprise a second DBR (140) disposed on the active region (120) and a top contact (150) disposed on the second DBR (140). The top contact (150) may be shaped such that the plurality of lasers are directed through the top contact (150). The device (100) may further comprise an array output coupler (160) disposed optically in line with the top contact (150) such that the plurality of lasers are directed into the array output coupler (160).

[0062] In some embodiments, the first DBR (130) may comprise an N-type DBR, a P-type DBR, or a combination thereof. In some embodiments, the second DBR (140) may comprise an N-type DBR, a P-type DBR, or a combination thereof.

[0063] In some embodiments, the bottom contact may comprise a substrate of a metal material. In some embodiments, the top contact may comprise a ring of a metal material. In some embodiments, the device may further comprise an electrical current generator for actuating the two or more emitters in the active region (120). In some embodiments, an output coupler may be defined as a semi-transparent dielectric mirror.

[0064] In some embodiments, each emitter of the plurality of emitters may comprise a chemical vapor deposition (CVD) diamond (121), an EP-VECSEL (122) disposed on the CVD diamond (121), an intracavity CVD diamond (123) disposed at least partially within a cavity disposed in the EP-VECSEL (122), an etalon (124) disposed parallel to and optically in line with the intracavity CVD diamond (123), a microlens array (125) disposed parallel to and optically in line with the etalon (124), and an emitter output coupler (126) disposed parallel to and optically in line with the microlens array (125). In some embodiments, the device (100) may further comprise a piezoelectric element operatively coupled to the emitter output coupler (126) of each emitter of the plurality of emitters, configured to move the emitter output coupler (126) such that a shape of the laser emitted by the emitter is changed. In some embodiments, the intracavity CVD diamond (123) may be fully disposed within the cavity, mostly disposed within the cavity, or mostly disposed outside of the cavity.

[0065] In some embodiments, the device (100) may further comprise a sampling component configured to sample a portion of the laser emitted by each emitter of the two or more emitters and lock a wavelength and phase of each emitter. In some embodiments, each laser of the plurality of lasers may comprise an HG beam. In some embodiments, the device (100) may further comprise an astigmatic mode converter disposed optically in line with the array output coupler (160), configured to convert the plurality of lasers from HG beams to Laguerre Gaussian (LG) beams. In some embodiments, the original emitters may have a common output coupler and combine to form a single higher order mode. In some embodiments, the system may comprise many output couplers configured to form a single laser beam through coherent beam combining. In some embodiments, the coherent beam combining may be accomplished with a piezoelectric element to control phase or by changing the current to each pixel.

[0066] Referring now to FIG. 5, the present invention features an electrical pumping vertical external-cavity surface-emitting laser (EP-VECSEL) system. In some embodiments, the system may comprise a power supply (200) and an EP-VECSEL device (100). The array may comprise a bottom contact (110), a first distributed Bragg reflector (DBR) (130) disposed on the bottom contact (110), and an active region (120) comprising a plurality of emitters disposed on the first DBR (130) configured to accept an electrical current at two or more emitters on the active region (120) such that the two or more emitters produce a plurality of lasers. The two or more emitters may be configured to form a desired Hermite Gaussian (HG) mode shape. The EP-VECSEL device (100) may further comprise a second DBR (140) disposed on the active region (120) and a top contact (150) disposed on the second DBR (140). The top contact (150) may be shaped such that the plurality of lasers are directed through the top contact (150). The EP-VECSEL device (100) may further comprise an array output coupler (160) disposed optically in line with the top contact (150) such that the plurality of lasers are directed into the array output coupler (160).

[0067] The system may further comprise a beam intrusion monitor (300) optically in line with the EP-VECSEL device (100), a targeting and relay system (400) operatively coupled to the beam intrusion monitor (300), a photovoltaic (PV) array (500) operatively coupled to the targeting and relay system (400), and a battery (600) operatively coupled to the PV array (500). In some embodiments, the system may further comprise a second beam intrusion monitor (700) operatively coupled to the targeting and relay system (400) and the PV array (500). This system may be used for perimeter alarm monitoring purposes. The beam intrusion monitors may be configured to detect an interruption in the beam(s) generated by the EP-VECSEL device of the present invention and generate a signal if an interruption is detected. This signal is sent to the targeting/relay system, which closes the circuit and shuts down the power supply in response to the signal, which activates an external alarm. The PV array is a power-generating component that provides power to both the power supply and the battery/load in response to light, thus energizing the system.

[0068] However, this perimeter alarm monitoring embodiment of the present invention is a non-limiting example, and the EP-VECSEL device of the presently claimed invention applies to any VECSEL-implemented device, such as laser cooling, spectroscopy, telecommunications, light sources for sensing applications (gas sensing, biomedical sensing, etc.), face and gesture recognition, proximity sensors, augmented reality displays, Light Detection and Ranging (LIDAR) systems for robotics, unmanned aerial vehicles, and autonomous cars, laser printers, optical mice, and smartphones.

[0069] FIG. 4 shows possible designs for each laser emitter. Here each pixel of the array can contain several elements, including but not limited to output couplers, lens arrays, etalons, filters, nonlinear crystals, etc. For coherent beam combining of the individual emitters, several schemes could be implemented. Typically, this would involve sampling a portion of the output from each emitter and locking the wavelength and phase of each emitter. Here, the best option would be a simple scheme that could adjust the electrical current to each emitter which would slightly adjust the wavelength of each emitter. Another option would be to add mechanical movement to the output coupler of each emitter which could be done with a piezoelectric element. This would be similar to adaptive optics that deform mirrors to account for atmospheric interference. To reiterate, each pixel (VECSEL pump spot area) can produce a variety of beam shapes or output powers. The pumping level, for example, can be used to control the phase for coherent beam combining. The current supplied to each pixel can also control the beam shape. The current can also control the optical phase of each pixel for coherent beam combining.

[0070] The scheme shown below in FIG. 5 shows one possible configuration for transferring laser energy from the source to the receiver. This is a simple configuration with a non-coherent beam combining for free-space laser energy transport. Of course, coherent beam combining could be implemented, as indicated earlier. In this scheme, it is possible to compensate for atmospheric interference/obstructions first by changing the beam shape and second by converting the HG beams emitted by the array into LG beams. These types of beams have been shown to propagate over longer distances. This allows the array to keep max power on target and also allows for the ability to maintain a desired beam pattern. As shown in the figure, additional features, including photovoltaics, beam monitors, relay systems, etc., can also be included.

[0071] In some embodiments, the top contact may further comprise an anti-reflective (AR) coating (155) to prevent the reflection of lasers to increase pump absorption and overall efficiency. The AR coating may comprise SiO.sub.2, Al.sub.2O.sub.3, Ta.sub.2O.sub.5, TiO.sub.2, or a combination thereof.

[0072] In some embodiments, as shown in FIG. 3, the active region of the EP-VECSEL of the present invention may comprise one or more sub-regions, each comprising one or more emitters. In some embodiments, the active region may comprise 1 to 50 sub-regions arranged in a square grid shape, a rectangular grid shape, or any polygonal shape encompassed by the active region. In some embodiments, each sub-region may comprise 1 to 100 emitters arranged in a square grid shape, a rectangular grid shape, or any polygonal shape encompassed by the sub-region.

[0073] In some embodiments, the microlens array (125) may comprise one or more rigid one- or two-dimensional arrangements of very tiny lenses, each with a diameter of 10 mm or less. A shape of each lens may comprise a square, a circle, a hexagon, a rectangle, or any other polygonal shape.

[0074] Referring now to FIG. 6, in some embodiments, the device may comprise one common output coupler that covers all emitters of the active region of the device. Current can be directed to each emitter independently to turn on the desired emitters to create the desired HG transverse Beam profile. This HG beam can then be modified via an astigmatic mode converter to generate Lg-shaped transverse profile beams. In some embodiments, each emitter may additionally be in line with one or more lens arrays, one or more mirror arrays, or a combination thereof.

[0075] Referring now to FIG. 7, in some embodiments, the plurality of emitters may all form individual laser cavities all acting independently and combining to generate the output of an incoherently combined laser beam. With the addition of a piezo element, the cavity length of each individual laser emitter can be changed, thus changing the optical phase of each laser. Through proper monitoring, the beams may then be combined coherently. Another method for coherent beam combining would be to change the current applied to each pixel which changes the thermal lensing of the semiconductor material which will in turn control the phase of each pixel. As with the use of a piezo, through proper monitoring, all the phases of the individual pixel emitters can be aligned for coherent beam combining.

[0076] Although there has been shown and described the preferred embodiment of the present invention, it will be readily apparent to those skilled in the art that modifications may be made thereto which do not exceed the scope of the appended claims. Therefore, the scope of the invention is only to be limited by the following claims. In some embodiments, the figures presented in this patent application are drawn to scale, including the angles, ratios of dimensions, etc. In some embodiments, the figures are representative only, and the claims are not limited by the dimensions of the figures. In some embodiments, descriptions of the inventions described herein using the phrase comprising includes embodiments that could be described as consisting essentially of or consisting of, and as such, the written description requirement for claiming one or more embodiments of the present invention using the phrase consisting essentially of or consisting of is met.

[0077] The reference numbers recited in the below claims are solely for ease of examination of this patent application, and are exemplary, and are not intended in any way to limit the scope of the claims to the particular features having the corresponding reference numbers in the drawings.