Semiconductor lasers

Claim 2

A hybrid index/gain-guided semiconductor laser (10), comprising a plurality of contiguous semiconductor layers deposited on a substrate, one or more of the layers forming an active region having a lower bandgap and higher index of refraction relative to at least cladding layers immediately adjacent thereto, the active region being approximate to a p-n junction when the laser is forward biased via primary current confinement means, permitting carrier recombination in at least one portion thereof and supporting radiation propogation under lasing conditions in an optical cavity (16) established between transverse end facets (15, 17) of the laser adjacent to the primary current confinement means, the laser having at least two regions of current confinement, the first of the regions containing the primary current confinement means and comprising a single current confinement stripe - (14) and extending from one laser facet toward the second of the regions, which has a pair of current confinement stripes (22, 24) parallel but axially offset from, the axis of the said stripe, and extending from the other laser facet toward said first region, the pair of stripes providing regions of lower refractive index in the laser compared to the region of the optical cavity established therebetween, which thereby fuctions as an index optical waveguide for the laser.

Claim 3

The laser of claim 1, wherein the primary stripe and the pair of offset stripes extend to the junction of the first and second regions.

Claim 4

The laser of claim 1 or 2, wherein the primary stripe and the pair of offset stripes arte contiguous at their inner ends.

Claim 5

The hybrid index/gain-guided semiconductor laser of claim 1 wherein said primary current confinement stripe is an axially aligned series of intermittent current confinement segments.

Claim 6

The hybrid index/gain-guided semiconductor laser of claim 4 wherein said offset current confinement stripes are an axially aligned series of intermittent current confinement segments adjacent each side of said primary current confinement stripe, said offset segments alternating spatially relative to said primary segments.

Claim 7

The hybrid index/gain-guided semiconductor laser of claim 1 wherein said second region with said offset current confinement stripes is provided at both ends of said first region.

Claim 8

The hybrid index/gain-guided semiconductor laser of any one of claims 1 through 6 wherein V-grooves are formed as part of said axially offset current confinement stripes to provide for sharper current confinement profiles into said lower refractive index regions of said second region.

Claim 9

A hybrid index/gain-guided semiconductor laser comprising a plurality of contiguous semiconductor layers deposited on a substrate, one or more of said layers forming an active region having a lower bandgap and higher index of refraction relative to at least cladding layers immediately adjacent thereto, said active region approximate to a p-n junction when, upon forward biasing via primary current confinement means, permitting carrier recombination in at least one portion thereof and supporting radiation propogation under lasing conditions in an optical cavity established between transverse end facets of the laser beneath said primary current confinement means, said laser having two regions of current confinement means, the first of said regions containing said primary current confinement means and extending from one laser facet toward the second of said regions, said second region having a pair of current confinement means parallel but axially offset relative to the axis of said primary current confinement means and extending from the other laser facet toward said first region, said axially offset current confinement means providing regions of lower refractive index in said laser compared to the region of said optical cavity es- ablished therebetween thereby functioning as index optical waveguide for said laser, said first region is electrically isolated from said second region so that said first region is independently pumped relative to said second region, means to varying the pumping current to said axially offset current confinement means regions to selectively change the refractive index differences between said axially offset current confinement means regions and said optical cavity region therebetween.

Claim 10

A hybrid index/gain-guided semiconductor laser comprising a plurality of contiguous semiconductor layers deposited on a substrate, one or more of said layers forming an active region having a lower bandgap and higher index of refraction relative to at least cladding layers immediately adjacent thereto, said active region approximate to a p-n junction when, upon forward biasing via primary current confinement means, permitting carrier recombination in at least one portion thereof and supporting radiation propogation under lasing conditions in an optical cavity established between transverse end facets of the laser beneath said primary current confinement means, said laser having two regions of current confinement means, the first of said regions containing said primary current confinement means and extending from one laser facet toward the second of said regions, said second region having a pair of current confinement means parallel but axially offset relative to the axis of said primary current confinement means and extending from the other laser facet toward said first region, said axially offset current confinement means providing regions of lower refractive index in said laser compared to the region of said optical cavity es- ablished therebetween thereby functioning as index optical waveguide for said laser, said first region is electrically isolated from said second region so that said first region is independently pumped relative to said second region, means to varying the pumping current to said axially offset current confinement means regions to selectively change the refractive index differences between said axially offset current confinement means regions and said optical cavity region therebetween.

Claim 11

A hybrid index/gain-guided semiconductor laser comprising a plurality of contiguous semiconductor laser comprising a plurality of contiguous semiconductor layers deposited on a substrate, one or more of said layers forming an active region having a lower bandgap and higher index of refraction relative to at least cladding layers immediately adjacent thereto, said active region approximate to a p-n junction when, upon forward biasing via primary current confinement means, permitting carrier recombination in at least one portion thereof and supporting radiation propogation under lasing conditions in an optical cavity established between transverse end facets of the laser beneath said primary current confinement means, said laser having two regions of current confinement means, the first of said regions containing said primary current confinement means and extending from one laser facet toward the second of said regions, said second region having a pair of current confinement means parallel but axially offset relative to the axis of said primary current confinement means and extending from the other laser facet toward said first region, said axially offset current confinement means providing regions of lower refractive index in said laser compared to the region of said optical cavity established therebetween thereby func- tionaing as index optical waveguide for said laser, said first region is electrically isolated from said second region and said second region is divided into two electrically isolated regions each including one or said axially offset current confinement means, each of said regions being independently pumped relative to the other of said regions, means to independently varying the pumping current to said axially offset current confinement means in said isolated regions to selectively change the refractive index differences therebetween to control the angularity of emission of a beam from said optical cavity.

Claim 12

A hybrid index/gain-guided semiconductor laser comprising a plurality of contiguous semiconductor laser comprising a plurality of contiguous semiconductor layers deposited on a substrate, one or more of said layers forming an active region having a lower bandgap and higher index of refraction relative to at least cladding layers immediately adjacent thereto, said active region approximate to a p-n junction when, upon forward biasing via primary current confinement means, permitting carrier recombination in at least one portion thereof and supporting radiation propogation under lasing conditions in an optical cavity established between transverse end facets of the laser beneath said primary current confinement means, said laser having two regions of current confinement means, the first of said regions containing said primary current confinement means and extending from one laser facet toward the second of said regions, said second region having a pair of current confinement means parallel but axially offset relative to the axis of said primary current confinement means and extending from the other laser facet toward said first region, said axially offset current confinement means providing regions of lower refractive index in said laser compared to the region of said optical cavity established therebetween thereby func- tionaing as index optical waveguide for said laser, said first region is electrically isolated from said second region and said second region is divided into two electrically isolated regions each including one or said axially offset current confinement means, each of said regions being independently pumped relative to the other of said regions, means to independently varying the pumping current to said axially offset current confinement means in said isolated regions to selectively change the refractive index differences therebetween to control the angularity of emission of a beam from said optical cavity.

Claim 13

A hybrid index/gain-guided semiconductor laser comprising a plurality of contiguous semiconductor layers deposited on a substrate, one or more of said layers forming an active region having a lower bandgap and higher index of refraction relative to at least cladding layers immediately adjacent thereto, said active region approxiamte to a p-n junction when, upon forward biasing via primary current confinement means, permitting carrier recombination in at least one portion thereof and supporting radiation propogation under lasing conditions in an optical cavity established between transverse end facets of the laser beneath said primary current confinement means, said laser having two regions of current confinement means, the first of said regions containing said primary current confinement means and extending from one laser facet toward the second of said regions, said second region having a pair of current confinement means parallel but axially offset relative to the axis of said primary current confinement means and extending from the other laser facet toward said first region, said axially offset current confinement means providing regions of lower refractive index in said laser compared to the region of said optical cavity established therebetween thereby functioning as an index optical waveguide for said laser, said axially offset current confinement means tapered at their inner end.

Claim 14

A hybrid index/gain-guided semiconductor laser comprising a plurality of contiguous semiconductor layers deposited on a substrate, one or more of said layers forming an active region having a lower bandgap and higher index of refraction relative to at least cladding layers immediately adjacent thereto, said active region approxiamte to a p-n junction when, upon forward biasing via primary current confinement means, permitting carrier recombination in at least one portion thereof and supporting radiation propogation under lasing conditions in an optical cavity established between transverse end facets of the laser beneath said primary current confinement means, said laser having two regions of current confinement means, the first of said regions containing said primary current confinement means and extending from one laser facet toward the second of said regions, said second region having a pair of current confinement means parallel but axially offset relative to the axis of said primary current confinement means and extending from the other laser facet toward said first region, said axially offset current confinement means providing regions of lower refractive index in said laser compared to the region of said optical cavity established therebetween thereby functioning as an index optical waveguide for said laser, said axially offset current confinement means tapered at their inner end.