High-speed modulation of InGaAs-GaAs strained-layer multiple-quantum-well lasers fabricated by chemically assisted ion-beam etching

Graded-index separate-confinement heterostructure (GRINSCH) strained-layer lasers with five In/sub 0.3/Ga/sub 0.7/As quantum wells have been fabricated with cavity lengths from 50 to 400 mu m using chemically assisted ion-beam etching (CAIBE) to form the laser mirrors. The dry-etching process is thermally assisted, which gives a reproducible etching rate. A minimum threshold-current value is observed at a cavity length of 50 mu m, showing that the multiquantum-well design is optimum for short-cavity lasers. A relaxation oscillation frequency of 10 GHz and a -3 dB bandwidth of 15 GHz have been measured on a 200*10 mu m mesa-structure device.<>