Monolithic multi-emitting laser device

Abstract

A monolithic laser device produces a plurality of spatially displaced emitting cavities in an active layer of a semiconductor body acting as a waveguide for light wave propagation under lasing conditions. Various means are disclosed to deflect and directly couple a portion of the optical wave propagation into one or more different spatially displaced emitting cavities to improve coherence and reduce beam divergence.

We claim: 
     
       1. In a monolithic laser device wherein one or more layers of semiconductor material are fabricated on a substrate, one of said layers forming .[.an.]. active .[.layer.]. .Iadd.means .Iaddend.for light wave propagation and generation under lasing conditions, means for forward biasing said active .[.layer.]. .Iadd.means .Iaddend.to produce a plurality of adjacent .Iadd., linear .Iaddend.light propagating and emitting portions therein, light guiding regions in said device .Iadd.intermediate of the ends of and .Iaddend.nonlinear relative to said emitting portions whereby .[.said.]. .Iadd.the .Iaddend.light waves produced in one portion of said active .[.layer.]. .Iadd.means .Iaddend.are deflected and coupled into one or more adjacent emitting portions of said active .[.layer.]. .Iadd.means .Iaddend., said regions provided by a refractive index change with which .[.said.]. .Iadd.the .Iaddend.light wave interacts while .[.said light wave is.].  within said regions and wherein said refractive index change is provided by the injected charge distribution determined by current confining means. 
     
     
       2. In a monolithic laser device wherein one or more layers of semiconductor material are fabricated on a substrate, one of said layers forming .[.an.]. active .[.layer.]. .Iadd.means .Iaddend.for light wave propagation and generation under lasing conditions, means for forward biasing said active .[.layer.]. .Iadd.means .Iaddend., means in .Iadd.and intermediate of the ends of .Iaddend.said device whereby .[.said.]. .Iadd.the .Iaddend.light waves produced in one portion of said active .[.layer.]. .Iadd.means .Iaddend.are deflected into one or more adjacent emitting portions of said active .[.layer.]. .Iadd.means .Iaddend., said deflection means provided by a refractive index change with which .[.said.]. .Iadd.the .Iaddend.light wave interacts while .[.said light wave is.]. within said deflection means and wherein said refractive index change is provided by an impurity profile. 
     
     
       3. The device of claim 2 wherein said impurity profile defines a plurality of .Iadd.linear .Iaddend.optical cavities, said cavities being coupled to one or more adjacent cavities by an interconnecting cavity formed by said profile. 
     
     
       4. The device of claim 3 wherein said optical cavities are angularly disposed relative to each other. 
     
     
       5. The device of claim 3 wherein said optical cavities are parallel. 
     
     
       6. The device of claim 3 wherein said optical cavities are unequally spaced relative to each other. 
     
     
       7. The device of claim 3 wherein some of said optical cavities are unequally spaced. 
     
     
       8. The device of claim 3 wherein all of said optical cavities are equally spaced relative to each other. 
     
     
       9. In a monolithic laser device wherein one or more layers of semiconductor material are fabricated on a substrate, one of said layers forming .[.an.]. active .[.layer.]. .Iadd.means .Iaddend.for light wave propagation and generation under lasing conditions, means for forward biasing said active .[.layer.]. .Iadd.means .Iaddend., means in .Iadd.and intermediate of the ends of .Iaddend.said device whereby .[.said.]. .Iadd.the .Iaddend.light waves produced in one portion of said active .[.layer.]. .Iadd.means .Iaddend.are deflected into one or more adjacent emitting portions of said active .[.layer.]. .Iadd.means .Iaddend., said deflection means provided by a refractive index change with which .[.said.]. .Iadd.the .Iaddend.light wave interacts while .[.said light wave is.]. within said deflection means and wherein said deflection means is a plurality of current confining channels, each of said current confining channels being coupled to an adjacent channel by an interconnecting current confining channel. 
     
     
       10. The device of claim 9 wherein said current confining channels are contact stripes. 
     
     
       11. The device of claim 9 wherein said current confining channels are angularly disposed relative to each other. 
     
     
       12. The device of claim 9 wherein said current confining channels are parallel. 
     
     
       13. The device of claim 9 wherein said current confining channels are unequally spaced relative to each other. 
     
     
       14. The device of claim 9 wherein some of said current confining channels are unequally spaced. 
     
     
       15. The device of claim 9 wherein all of said current confining channels are equally spaced relative to each other. 
     
     
       16. In a monolithic laser device wherein one or more layers of semiconductor material are fabricated on a substrate, one of said layers forming .[.an.]. active .[.layer.]. .Iadd.means .Iaddend.for light wave propagation and generation under lasing conditions, means for forward biasing said active .[.layer.]. .Iadd.means .Iaddend., means in .Iadd.and intermediate of the ends of .Iaddend.said device whereby .[.said.]. .Iadd.the .Iaddend.light waves produced in one portion of said active .[.layer.]. .Iadd.means .Iaddend.are deflected into one or more adjacent emitting portions of said active .[.layer.]. .Iadd.means .Iaddend., said deflection means provided by a refractive index change with which .[.said.]. .Iadd.the .Iaddend.light wave interacts while .[.said light wave is.]. within said deflection means and wherein said refractive index change is provided by a material composition change. 
     
     
       17. The device of claim 16 wherein the material composition change defines a plurality of .Iadd.linear .Iaddend.optical cavities, said cavities being coupled to one or more adjacent cavities by an interconnecting cavity formed by said material composition change. .[.18. The device of claim 17 wherein said optical cavities are angularly disposed relative to each 
     
     
        other..]. 19. The device of claim 17 wherein said optical cavities are 
     
     
        parallel. 20. The device of claim 17 wherein said optical cavities are 
     
     
        unequally spaced relative to each other. 21. The device of claim 17 
     
     
        wherein some of said optical cavities are unequally spaced. 22. The device of claim 17 wherein all of said optical cavities are equally spaced 
     
     
        relative to each other. 23. In a monolithic laser device wherein one or more layers of semiconductor material are fabricated on a substrate, one of said layers forming .[.an.]. active .[.layer.]. .Iadd.means .Iaddend.for light wave propagation and generation under lasing conditions, means for forward biasing said active .[.layer.]. .Iadd.means .Iaddend., means in .Iadd.and intermediate of the ends of .Iaddend.said device whereby .[.said.]. .Iadd.the .Iaddend.light waves produced in one portion of said active .[.layer.]. .Iadd.means .Iaddend.are deflected into one or more adjacent emitting portions of said active .[.layer.]. .Iadd.means .Iaddend., said deflection means provided by a refractive index change with which .[.said.]. .Iadd.the .Iaddend.light wave interacts while .[.said light wave is.]. within said deflection means and wherein said refractive index change is provided by a material thickness change. 
     
     
          . The device of claim 23 wherein a plurality of interconnecting channels are provided in said substrate to provide said material thickness change. 
     
     
         5. The device of claim 23 wherein the material thickness change defines a plurality of .Iadd.linear .Iaddend.optical cavities, said cavities being coupled to one or more adjacent cavities by an interconnecting cavity formed by said material thickness change. .[.26. The device of claim 25 wherein said optical cavities are angularly disposed relative to each 
     
     
        other..]. 27. The device of claim 25 wherein said optical cavities are 
     
     
        parallel. 28. The device of claim 25 wherein said optical cavities are 
     
     
        unequally spaced relative to each other. 29. The device of claim 25 
     
     
        wherein some of said optical cavities are unequally spaced. 30. The device of claim 25 wherein all of said optical cavities are equally spaced 
     
     
        relative to each other. 31. In a monolithic laser device wherein one or more layers of semiconductor material are fabricated on a substrate, one of said layers forming .[.an.]. active .[.layer.]. .Iadd.means .Iaddend.for light wave propagation and generation under lasing conditions, current confining means for forward biasing selected portions of said active .[.layer.]. .Iadd.means .Iaddend.to produce two or more .Iadd.linear and spatially disposed .Iaddend.lasing and .Iadd.light .Iaddend.emitting cavities in said active .[.layer.]. .Iadd.means .Iaddend., and a light coupling region between said .Iadd.linear light emitting .Iaddend.cavities to deflect a portion of the light wave 
     
     
        propagation in one cavity to one or more adjacent emitting cavities. 32. In a monolithic laser device wherein one or more layers of semiconductor material are fabricated on a substrate, one of said layers forming .[.an.]. active .[.layer.]. .Iadd.means .Iaddend.for light wave propagation and generation under lasing conditions, a plurality of current confining means for forward biasing selected portions of said active .[.layer.]. .Iadd.means .Iaddend.to produce a plurality of .Iadd.linear light .Iaddend.emitting cavities therein, and light deflecting means .Iadd.intermediate of the ends of said cavities and .Iaddend.coupling each of said current confining means to one or more adjacent current confining means wherein said current confining means comprises a plurality of parallel contact stripes on the surface thereof, each of said stripes being coupled to an adjacent stripe by an interconnecting stripe means. 
     
     
            The device of claim 32 wherein said interconnecting stripe means are 
     
     
        curved stripe sections. 34. The device of claim 32 wherein said interconnecting stripe means are transversely disposed stripe sections. 
     
     
            The device of claim 34 wherein said sections are geometrically 
     
     
        staggered relative to each other along the length of said device. 36. The device of claim 32 wherein said interconnecting stripe means are 
     
     
        criss-crossing stripe sections. 37. The device of claim 32 wherein said interconnecting stripe means comprises a single wide contact stripe transversely disposed relative to said parallel .[.contract.]. .Iadd.contact .Iaddend.stripes, said transversely disposed stripe being 
     
     
        several times wider than said parallel contact stripes. 38. The device of claim 37 wherein said transversely disposed stripe is perpendicular to 
     
     
        said parallel contact stripes. 39. The device of claim 32 wherein said interconnecting stripe means comprises a y-shape stripe configuration connecting the ends of a pair of said parallel contact stripes at one end 
     
     
        of said device. 40. The device of claim 32 wherein said contact stripes are disposed at an angle relative to the longitudinal axis of said device. 
     
     
        1. The device of claim 32 wherein said current confining means comprises a plurality of contact stripes on the surface thereof, said stripes being angularly disposed relative to each other and said interconnecting stripe 
     
     
        means connecting the ends of adjacently disposed contact stripes. 42. In a monolithic laser device wherein one or more layers of semiconductor materials are fabricated on a substrate, one of said layers forming .[.an.]. active .[.layer.]. .Iadd.means .Iaddend.for light wave generation and propagation, means for forward biasing said active .[.layer.]. .Iadd.means .Iaddend.to produce a light wave in at least one linear light propagating region of said active .[.layer.]. .Iadd.means .Iaddend.and an adjacent light guiding region .Iadd.intermediate of the ends of and .Iaddend.coupled to said one region to deflect and couple a portion of said light wave in said one region into other such regions formed in said active .[.layer.]. .Iadd.means .Iaddend.which are linear and spatially 
     
     
        displaced from said one region. 43. In a monolithic laser device wherein one or more layers of semiconductor materials are fabricated on a substrate, one of said layers forming .[.an.]. active .[.layer.]. .Iadd.means .Iaddend.for light wave generation and propagation, means for forward biasing said active .[.layer.]. .Iadd.means .Iaddend.to produce a light wave in at least one region of said active .[.layer.]. .Iadd.means .Iaddend.and means to deflect and couple a portion of said light wave in said one region into other regions of said active .[.layer.]. .Iadd.means .Iaddend.spatially displaced from said one region and wherein said first and second mentioned means include means to confine current to selected portions of said active layer to produce multiple .Iadd.linear light 
     
     
        .Iaddend.emitting cavities. 44. In a monolithic laser device wherein laser device wherein one or more layers of semiconductor materials are fabricated on a substrate, one of said layers forming .[.an.]. active .[.layer.]. .Iadd.medium .Iaddend.for light wave generation and propagation, means for forward biasing said active .[.layer.]. .Iadd.medium .Iaddend.to produce a light wave in at least one region of said active .[.layer.]. .Iadd.medium .Iaddend.and means to deflect and couple a portion of said light wave in said one region into other regions of said active .[.layer.]. .Iadd.medium .Iaddend.spatially displaced from said one region and wherein said first mentioned means comprises a plurality of current confining channels, said second mentioned means comprises a plurality of interconnecting current confining channels .Iadd.intermediate of the ends of the ends of said regions. .Iaddend.. 
     
     
            The device of claim 44 wherein said current confining channels comprises a plurality of spaced stripes, said interconnecting current confining channels comprise a plurality of interconnecting stripes, at least one such interconnecting stripe being disposed between adjacent 
     
     
        stripes. 46. In a monolithic laser device wherein one or more layers of semiconductor materials are fabricated on a substrate, one of said layers forming .[.an.]. active .[.layer.]. .Iadd.medium .Iaddend.for light wave generation and propagation.Iadd., .Iaddend.means for forward biasing said active .[.layer.]. .Iadd.medium .Iaddend.to produce a light wave in at least one region of said active .[.layer.]. .Iadd.medium .Iaddend.and means to deflect and couple a portion of said light wave in said one region into other regions of said active .[.layer.]. .Iadd.medium .Iaddend.spatially displaced from said one region and wherein said first mentioned means comprises a plurality of spaced mesa structures including .[.all.]. .Iadd.portions .Iaddend.of said layers .Iadd.and said active medium .Iaddend., said mesa structures separated from each other by a medium of lower refractive index than said active .[.layer.]. .Iadd.medium .Iaddend., and said second mentioned means comprises a plurality of interconnecting mesa structures .Iadd.intermediate of the ends of said mesa structures .Iaddend., at least one such interconnecting mesa 
     
     
        structure being disposed between adjacent mesa structures. 47. In a monolithic laser device wherein one or more layers of semiconductor materials are fabricated on a substrate, one of said layers forming .[.an.]. active .[.layer.]. .Iadd.medium .Iaddend.for light wave generation and propagation, means for forward biasing said active .[.layer.]. .Iadd.medium .Iaddend.to produce a light wave in at least one region of said active .[.layer.]. .Iadd.medium .Iaddend.and means to deflect and couple a portion of said light wave in said one region into other regions of said active .[.layer.]. .Iadd.medium .Iaddend.spatially displaced from said one region and wherein said first mentioned means comprises a plurality of spaced channels in the surface of said substrate, said second mentioned means comprises a plurality of interconnecting channels in said substrate .Iadd.intermediate of the ends of the ends of said spaced channels .Iaddend., at least one such interconnecting channel 
     
     
        being disposed between adjacent channels. 48. In a monolithic laser device wherein one or more layers of semiconductor materials are fabricated on a substrate, one of said layers forming .[.an.]. active .[.layer.]. .Iadd.means .Iaddend.for light wave generation and propagation, means for forward biasing said active .[.layer.]. .Iadd.means .Iaddend.to produce a light wave in at least one region of said active .[.layer.]. .Iadd.means .Iaddend.and means to deflect and couple a portion of said light wave in said one region into other regions of said active .[.layer.]. .Iadd.means .Iaddend.spatially displaced from said one region and wherein said .[.second.]. .Iadd.third .Iaddend.mentioned means is a periodic grating disposed in said layers such that said light wave interacts with said grating being at an angle relative to the direction of light wave 
     
     
        propagation. 49. In a monolithic laser device wherein one or more layers of semiconductor materials are fabricated on a substrate, one of said layers forming .[.an.]. active .[.layer.]. .Iadd.medium .Iaddend.for light wave generation and propagation, means for forward biasing said active .[.layer.]. .Iadd.medium .Iaddend.to produce a light wave in at least one region of said active .[.layer.]. .Iadd.medium .Iaddend.and means to deflect and couple a portion of said light wave in said one region into other regions of said active .[.layer.]. .Iadd.medium .Iaddend.spatially displaced from said one region and wherein said first mentioned means comprises a plurality of current confining channels, said second mentioned means characterizes said current confining channels as each being disposed 
     
     
        at an angle relative to the longitudinal axis of said device. 50. The device of claim 49 wherein said current confining channels are parallel. 
     
     
          . The device of claim 49 wherein said current confining channels are angularly disposed relative to each other and coupled to an adjacent 
     
     
        current confining channel by interconnecting channel means. 52. The device of claims 49, 50 or 51 wherein said current confining channels are contact 
     
     
        stripes. 53. In a monolithic laser device wherein one or more layers of semiconductor materials are fabricated on a substrate, one of said layers forming .[.an.]. active .[.layer.]. .Iadd.means .Iaddend.for light wave generation and propagation, means for forward biasing said active .[.layer.]. .Iadd.means .Iaddend.to produce a light wave in at least one region of said active .[.layer.]. .Iadd.means .Iaddend.and means to deflect and couple a portion of said light wave in said one region into other regions of said active .[.layer.]. .Iadd.means .Iaddend.spatially displaced from said one region and wherein said regions are impurity in said device, said impurity profile defining a plurality of .Iadd.linear .Iaddend.optical cavities, said .Iadd.linear optical .Iaddend.cavities being coupled to one or more adjacent cavities by an interconnecting cavity formed by said profile .Iadd.and intermediate of the ends of said cavities .Iaddend.. .Iadd.54. The device of claim 31 wherein said linear cavities are coupled by said light coupling regions intermediate of the ends of said linear cavities. .Iaddend. .Iadd.55. The device of claim 31 wherein said linear cavities are angularly disposed relative to adjacent, linear cavities and are coupled to said adjacent, linear cavities by said light coupling regions at the ends of said cavities. .Iaddend. .Iadd.56. The device of claim 43 wherein said linear emitting cavities are coupled by said deflection means intermediate of the ends of said linear emitting cavities. .Iaddend. .Iadd.57. The device of claim 43 wherein said linear emitting cavities are angularly disposed relative to adjacent, linear cavities and are coupled to said adjacent, linear cavities by said deflection means at the ends of said cavities. .Iaddend.