Abstract A strip buried double heterostructure laser having a pair of opposite-conductivity-type, wide bandgap cladding layers separated by a narrower bandgap active region. The active region includes a low-loss waveguide layer and contiguous therewith a narrower bandgap active layer in the form of a narrow strip extending along the longitudinal (resonator) laser axis. Lateral current confinement means, such as reversed biased p-n junctions, constrain pumping current in a narrow channel through the active layer. Lasers of this type exhibit relatively high pulsed power outputs (e. g., 400 mW), linear L-I characteristics, stable fundamental transverse mode and single longitudinal mode oscillation. In another embodiment waveguide layer surfaces adjacent the active layer have distributed feedback gratings. Also described are techniques for shaping the active layer without introducing debilitating defects therein, as well as procedures for LPE growth on Al-containing Group III-V compound layers which are exposed to processing in the ambient.
Method of growing a Group III-V compound epitaxial second layer from the liquid phase on an Al-containing Group III-V compound first layer, CHARACTERIZED BY forming a non-Al-containing Group III-V compound epitaxial protective layer about several ten nanometers thick on a major surface of the Al-containing first layer before exposing the first layer to an ambient which would otherwise oxidize the major surface, exposing the layers to the ambient, the protective layer preventing oxidation of the growth surface, bringing a molten solution of the Group III-V compound of the second layer into contact with the protective layer so as to dissolve the protective layer in the solution, and epitaxially growing the second layer directly on the major surface of the Al-containing first layer.
Claim 2
Dependent Claim
122 words
Method of growing a Group III-V compound epitaxial second layer from the liquid phase on an Al-containing Group III-V compound first layer, CHARACTERIZED BY forming a non-Al-containing Group III-V compound epitaxial protective layer about several ten nanometers thick on a major surface of the Al-containing first layer before exposing the first layer to an ambient which would otherwise oxidize the major surface, exposing the layers to the ambient, the protective layer preventing oxidation of the growth surface, bringing a molten solution of the Group III-V compound of the second layer into contact with the protective layer so as to dissolve the protective layer in the solution, and epitaxially growing the second layer directly on the major surface of the Al-containing first layer.
Claim 3
Dependent Claim
13 words
Method according to claim 1, CHARACTERIZED IN THAT the protective layer comprises GaAs.
Claim 4
Dependent Claim
17 words
Method according to either claim 1 or 2, CHARACTERIZED IN THAT first and second layers comprise AlGaAs.
Claim 5
Dependent Claim
34 words
Method according to any of claims 2 - 3, CHARACTERIZED IN THAT the forming step includes epitaxially growing a relatively thick protective layer, and thinning the protective layer until only several ten nanometers remain.
Claim 6
Dependent Claim
44 words
Method according to claim 4 CHARACTERIZED IN THAT the thinning step comprises anodizing the protective layer to form a native oxide which consumes a portion of the layer and removing the oxide layer so that only several ten nanometer of the protective layer remains.
Claim 7
Dependent Claim
55 words
Method according to any one of claims 1 - 5, CHARACTERIZED IN THAT the first layer is grown by molecular beam epitaxy (MBE) and, without removing the first layer from the MBE growth chamber, the protective layer is formed by directly depositing by MBE the about several ten nanometers of the non-Al-containing Group III-V compound.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.