Semiconductor blue-green laser diodes

according to US Patent Number: 5371756 direct blue-green laser diodes can be manufactured using CdZnSe, ZnSSe, and ZnSe, for each of the p-type clad layer and the n-type clad layer contains at least one of ZnSSe, ZnSe and ZnMgSSe. This direct blue-green laser diodes would be cheaper to manufacture compared to diode pumped solid state lasers using high-power infrared diodes and then doubling or tripling the frequency to produce visible light.

Here are the patent claims of the said patent:

1. A semiconductor blue-green light emitting device in a double heterostructure configuration, comprising:

a substrate;

a light emitting layer which contains at least one of CdZnSe, ZnSSe, and ZnSe;

a p-type clad layer and an n-type clad layer each of which contains at least one of ZnSSe, ZnSe and ZnMgSSe and which are provided at two sides of said light emitting layer, respectively;

a cap layer of (Al.sub.X Ga.sub.1-X).sub.0.5 In.sub.0.5 P (0.ltoreq.X.ltoreq.1) which is deposited on said clad layer located at an opposite side of said light emitting layer from said substrate; and

a contact layer of Al.sub.X Ga.sub.1-X As (0.ltoreq.X.ltoreq.1) which is deposited on said cap layer.

2. A semiconductor blue-green light emitting device according to claim 1, in which said cap layer and said contact layer are made of organic group V materials.

3. A semiconductor blue-green light emitting device according to claim 1, which further comprises a dielectric insulating layer which is formed on said contact layer and which has a stripe opening, and a metal electrode which is provided in said stripe opening.

4. A semiconductor blue-green light emitting device according to claim 1, in which said clad layer disposed at the opposite side of said light emitting layer from the substrate is configured in a mesa stripe with its two side surfaces and two laterally positioned surfaces being covered with dielectric insulating films, respectively.