Manufacturable vertical extended cavity surface emitting laser arrays

1. A semiconductor vertical, extended-cavity, surface-emitting laser array with intra-cavity nonlinear frequency doubling, comprising:

an electrically pumped, surface-emitting semiconductor gain chip having an array of emitters formed in a common semiconductor substrate, each emitter generating light about a fundamental wavelength;

an end reflector spaced apart from said surface-emitting semiconductor gain chip to define an extended cavity for each of said array of emitters, said end reflector having a high reflectivity at the fundamental laser wavelength;

a nonlinear crystal disposed within the extended cavity to provide frequency doubling of light for the entire array of emitters;

a wavelength control element disposed within the extended cavity to provide wavelength control for the entire array of emitters; and

a polarization control element disposed within the extended cavity to provide polarization control for the entire array of emitters;

said surface-emitting laser array having an optical unit having the functionality of at least two of said gain chip, said end reflector, said nonlinear crystal, said wavelength control element, and said polarization control element to reduce the number of components that must be aligned during packaging; and

a dichroic beam-splitter having at least one prism to selectively redirect out of the cavity frequency doubled light traveling back to said gain chip.

2. The laser array of claim 1 , wherein said polarization control element comprises a dichroically coated beamsplitter including at least one prism, said beamsplitter coupling light at a second harmonic frequency out of said extended cavity.

3. The laser array of claim 2 , herein said cavity has a forward direction for beams traversing towards said end reflector and a backwards direction for beams traversing towards said gain chip, said beamsplitter receiving and re-directing second-harmonic beams traversing in the backward direction outside of the laser cavity by about ninety degrees.

4. The laser array of claim 2 , wherein said cavity has a forward direction for beams traversing towards said end reflector and a backwards direction for beams traversing towards said gain chip, said beamsplitter receiving and re-directing second-harmonic beams traversing in the backward direction by about one-hundred and eighty degrees.

5. The laser array of claim 4 wherein said backward propagating second harmonic beams are reflected in the same direction as second harmonic beams traveling in a forward direction coupled out of said extended cavity via said end reflector such that two sets of second harmonic beams are coupled out of the cavity in the forward direction.

6. The laser array of claim 5 , further comprising a waveplate configured to rotate the polarization of one of the sets of second harmonic beams coupled out of the cavity to decrease speckle.

7. The laser array of claim 5 , wherein said beamsplitter is a monolithic element.

8. The laser array of claim 7 , wherein said monolithic element is a single prism.

9. The laser array of claim 8 , wherein facets of said single prism are coated to selectively redirect light at the second harmonic frequency.

10. A semiconductor, vertical, extended-cavity, surface-emitting laser array with intra-cavity nonlinear frequency doubling, comprising:

an electrically pumped, surface-emitting semiconductor gain chip having an array of emitters formed in a common semiconductor substrate, each emitter generating light about a fundamental wavelength;

an end reflector spaced apart from said surface-emitting semiconductor gain chip to define an extended cavity for each of said array of emitters, said end reflector having a high reflectivity at the fundamental laser wavelength;

a nonlinear crystal disposed within the extended cavity to provide frequency doubling of light for the entire array of emitters;

a wavelength control element disposed within the extended cavity to provide wavelength control for the entire array of emitters; and

a dichroic beamsplitter selectively coupling light at a second harmonic frequency out of said extended cavity, said dichroic beamsplitter comprising at least one prism;

said surface-emitting laser array having an optical unit having the functionality of at least two of said gain chip, said end reflector, said nonlinear crystal, said wavelength control element, and said polarization control element to reduce the number of components that must be aligned during packaging.

11. The laser array of claim 10 , wherein said cavity has a forward direction for beams traversing towards said end reflector and a backwards direction for beams traversing towards said gain chip, said beamsplitter receiving and re-directing second-harmonic beams traversing in the backward direction outside of the laser cavity by about ninety degrees.

12. The laser array of claim 10 , wherein said cavity has a forward direction for beams traversing towards said end reflector and a backwards direction for beams traversing towards said gain chip, said beamsplitter receiving and re-directing second-harmonic beams traversing in the backward direction by about one-hundred and eighty degrees.

13. The laser array of claim 12 wherein said backward propagating second harmonic beams are reflected in the same direction as second harmonic beams traveling in a forward direction coupled out of said extended cavity via said end reflector such that two sets of second harmonic beams are coupled out of the cavity in the forward direction.

14. The laser array of claim 13 , further comprising a waveplate configured to rotate the polarization of one of the sets of second harmonic beams coupled out of the cavity to decrease speckle.

15. The laser array of claim 8 , wherein said beamsplitter is a monolithic element.

16. The laser array of claim 15 , wherein said monolithic element is a single prism.

17. The laser array of claim 16 , wherein facets of said single prism are coated to selectively redirect light at the second harmonic frequency.