Wide-range tunable semiconductor lasers using asymmetric dual quantum wells

Using asymmetric dual quantum wells for the laser material, the semiconductor lasers are broadly tunable. In a grating coupled ring cavity, the semiconductor laser is continuously tunable from 766 to 856 nm using a 400-μm semiconductor laser amplifier in the cavity. This letter also demonstrates that the grating coupled ring cavity could well eliminate the amplified stimulated emission noise and about 40-dB amplified spontaneous emission (ASE) suppression ratio is obtained over the entire tuning range.