Multi-wavelength VCSEL array to reduce speckle

1. A method comprising:

forming an illuminator comprising a light source configured to originate an illumination beam, wherein the light source comprises an array of vertical-cavity surface emitting lasers (VCSELs) sharing at least one common electrode and configured to produce different emission wavelengths to form the illumination beam, including a first VCSEL having a first laser emission wavelength, and a second VCSEL having a second laser emission wavelength different than the first laser emission wavelength; and

forming an illumination path to direct the illumination beam towards an object, wherein the different emission wavelengths are configured to produce a full-width-half-maximum of between approximately 3 nm and 20 nm for the illumination beam.

2. The method of claim 1 , wherein the forming the illuminator comprises forming a first laser cavity length for the first VCSEL and forming a second laser cavity length different than the first cavity length for the second VCSEL.

3. The method of claim 1 , wherein the forming the illuminator comprises forming a first set of mirrors configured to define a first resonant cavity for the first VCSEL, and forming a second set of mirrors configured to define a second resonant cavity, different than the first resonant cavity, for the second VCSEL.

4. The method of claim 3 , wherein the first and second VCSELs each comprise a vertical external cavity surface emitting laser (VECSEL), and wherein the first and second set of mirrors comprise mirrors forming an external cavity for both the first and second VECSELs.

5. The method of claim 1 , wherein the forming the illuminator comprises forming one or more distributed Bragg reflectors (DBRs), wherein the first VCSEL includes a first effective optical path length formed by at least one of the DBRs, and the second VCSEL includes a second optical path length, different from the first optical path length, formed by at least one of the DBRs.

6. The method of claim 1 , wherein the forming the illuminator comprises forming the VCSELs in a two dimensional array having a spectral gradient from relatively short to relatively long wavelengths varying spatially from one side of the array to another, radially outward from a center of the array, randomly across the array, and/or within sub-sections of the array.

7. The method of claim 1 , wherein the forming the illuminator comprises forming a first emitter diameter for the first VCSEL and a second emitter diameter different than the first emitter diameter for the second VCSEL.

8. The method of claim 1 , wherein the forming the illuminator comprises forming active cavity regions for the first VCSEL and the second VCSEL according to different refractive indexes.

9. The method of claim 1 , wherein:

the forming the illuminator comprises forming a temperature variation structure coupled to the array of VCSELs to provide, at least in part, the different emission wavelengths; and

the temperature variation structure comprises one or more patterned heat spreaders, one or more solders, and/or one or more current injection gradient structures.

10. The method of claim 1 , wherein:

the forming the illuminator comprises forming the array of VCSELs to distribute the different emission wavelengths substantially within the near infrared and/or short-wave infrared spectrums; and

the forming the illumination path comprises forming a microlens array aligned with each VCSEL of the array of VCSELs to collimate the illumination beam.

11. The method of claim 1 , further comprising forming an imager and/or a lens assembly configured to receive light from the illumination beam reflected from the object, wherein the different emission wavelengths are configured to reduce a peak to peak speckle noise intensity, as measured by the imager, by more than fifty percent as compared to a single emission wavelength illumination beam.

12. A method comprising:

generating an illumination beam based on power received from a power source and regulated by a power controller, wherein the light source comprises an array of vertical-cavity surface emitting lasers (VCSELs) sharing at least one common electrode and configured to produce different emission wavelengths to form the illumination beam, including a first VCSEL having a first laser emission wavelength, and a second VCSEL having a second laser emission wavelength different than the first laser emission wavelength;

directing the illumination beam towards an object;

receiving light from the illumination beam reflected from a surface of the object; and

providing the received light to one or more photosensitive elements to capture imaging information of the object;

wherein the different emission wavelengths are configured to produce a FWHM of between approximately 3 nm and 20 nm for the illumination beam and to reduce a peak to peak speckle noise intensity, as measured by the one or more photosensitive elements, by more than fifty percent as compared to a single emission wavelength illumination beam.

13. The method of claim 12 , wherein the first VCSEL includes a first laser cavity length and the second VCSEL includes a second laser cavity length different than the first cavity length.

14. The method of claim 12 , wherein the first VCSEL includes a first set of mirrors configured to define a first resonant cavity, and the second VCSEL includes a second set of mirrors configured to define a second resonant cavity different than the first resonant cavity.

15. The method of claim 14 , wherein the first and second VCSELs each comprise a vertical external cavity surface emitting laser (VECSEL), and wherein the first and second set of mirrors include mirrors forming an external cavity for both the first and second VECSELs.

16. The method of claim 12 , the light source further comprising:

one or more distributed Bragg reflectors (DBRs), wherein the first VCSEL includes a first effective optical path length formed by at least one of the DBRs, and the second VCSEL includes a second optical path length, different from the first optical path length, formed by at least one of the DBRs.

17. The method of claim 12 , wherein the array of VCSELs are arranged in a two dimensional array having a spectral gradient from relatively short to relatively long wavelengths varying spatially from one side of the array to another, radially outward from a center of the array, randomly across the array, and/or within sub-sections of the array, and wherein the two dimensional array comprises a circular, square, or pentagonal shape.

18. The method of claim 12 , wherein the first VCSEL includes a first emitter diameter and the second VCSEL includes a second emitter diameter different than the first emitted diameter.

19. The method of claim 12 , wherein active cavity regions of the first VCSEL and the second VCSEL comprise different refractive indexes.

20. The method of claim 12 , wherein:

the different emission wavelengths are substantially within the near infrared and/or short-wave infrared spectrums;

the one or more photosensitive elements are sensitive to the near infrared and/or short-wave infrared spectrums; and

the imaging information is configured to provide night vision, target recognition, target identification, range finding, and/or detection of the object and/or other elements within a scene illuminated by the illumination beam.