Claims
- 1. A precursor quantum well microstructure for a tunable laser, comprising a quantum well layer between a pair of barrier layers, and a defect reservoir formed by ultraviolet radiation within a near-surface region and varying across a surface of the microstructure, said defect reservoir being capable of acting as a source or sink of defects during a subsequent thermal anneal to induce defect-mediated quantum-well intermixing at the quantum well-barrier layer heterointerface.
- 2. A precursor quantum well microstructure as claimed in claim 1, wherein said defect reservoir is formed across said surface in a predetermined pattern.
- 3. A precursor quantum well microstructure as claimed in claim 1, wherein said near-surface region is about 100 nm or less.
- 4. A precursor quantum well microstructure as claimed in claim 1, comprising quantum wells of InGaAs embedded between InGaAsP barrier layers.
- 5. A tunable laser including a precursor quantum well microstructure as claimed in claim 1 that has been subjected to a thermal anneal to induce defect-mediated quantum well intermixing.
CROSS REFERENCE TO RELATED APPLICATION
This application is a divisional application under 35 CFR 121 of U.S. patent application Ser. No. 09/654,616 filed Sep. 1, 2000 now U.S. Pat. No. 6,514,784.