Variable wavelength laser diode

Claim 2

A variable wavelength semiconductor laser comprising: a first semiconductor layer; a second semiconductor layer having first and second surfaces, said first surface contiguous with said first semiconductor layer forming a light emitting junction at the interface of said first and second semiconductor layers; an oxide layer contiguous with said second surface of said second semiconductor layer; said oxide layer having a first opening of cross sectional area positioned within a first edge of said oxide layer and a second opening of cross sectional area larger than the first opening and positioned in a second edge opposite the first edge; and tapered passage means positioned between said first and second openings completing a passage therethrough.

Claim 3

The laser set forth in claim 1 together with fiber optic means positioned in optical alignment with the tapered passage means for enabling the laser to operate as a modulating transmitter.

Claim 4

The laser set forth in claim 1 wherein the tapered passage means is characterized as an elongated gap.

Claim 5

The laser set forth in claim 1 wherein the tapered passage means in characterized as an elongated cavity.

Claim 6

The laser set forth in claim 1 wherein said first opening in the nature of a square-shaped gap is centrally located along the first edge of the oxide layer and said second opening in the nature of a rectangular gap is centrally located along an opposite edge of the oxide layer thereby creating a tapered elongated gap.

Claim 7

The laser set forth in claim 1 wherein the oxide layer is sandwiched between said second semiconductor layer and a third layer of conductive material.

Claim 8

The laser set forth in claim 3 wherein the oxide layer has upper and lower surfaces tapered in substantially parallel relation to corresponding surfaces of the elongated gap.

Claim 9

The laser set forth in claim 4 wherein the oxide layer has upper and lower surfaces tapered in substantially parallel relation to corresponding surfaces of the elongated cavity.

Claim 10

The laser set forth in claim 6 wherein the second and third layers have untapered interfaces with the oxide layer.

Claim 11

The laser set forth in claim 6 wherein the second and third layers have tapered interfaces mating with the oxide layer.

Claim 12

A variable wavelength semiconductor laser comprising: first and second semiconductor layers; an active semiconductor layer intermediate to and contiguous with said first and second layers forming a light emitting junction at the interface between a first surface of said second layer and said active layer; said first and second layers having a higher bandgap and a lower refractive index than said active layer so that light propagates in said active layer perpendicular to the junction by waveguiding action; an oxide layer contiguous with a second surface of said second layer and in opposition to said junction; said oxide layer having a first opening of rectangular cross sectional area positioned within a first edge of said oxide layer and a second opening of rectangular cross sectional area larger than the first opening and positioned in an opposite edge of said oxide layer; and tapered passage means positioned between said first and second openings completing a passage therethrough.

Claim 13

A variable wavelength semiconductor laser comprising: first and second semiconductor layers; an active semiconductor layer intermediate to and contiguous with said first and second layers forming a light emitting junction at the interface between a first surface of said second layer and said active layer; said first and second layers having a higher bandgap and a lower refractive index than said active layer so that light propagates in said active layer perpendicular to the junction by waveguiding action; an oxide layer contiguous with a second surface of said second layer and in opposition to said junction; said oxide layer having a first opening of rectangular cross sectional area positioned within a first edge of said oxide layer and a second opening of rectangular cross sectional area larger than the first opening and positioned in an opposite edge of said oxide layer; and tapered passage means positioned between said first and second openings completing a passage therethrough.