InGaN multiquantum-well-structure laser diodes with GaN-AlGaN modulation-doped strained-layer superlattices

InGaN multiquantum-well-structure (MQW) laser diodes with Al/sub 0.14/Ga/sub 0.86/N-GaN modulation doped strained-layer superlattice (MD-SLS) cladding layers grown on an epitaxially laterally overgrown GaN substrate was demonstrated to have a lifetime of more than 2300 h under the condition of room-temperature continuous-wave operation. The self-pulsation was observed with a frequency of 3.5 GHz. The relative intensity noise less than -145 dB/Hz was obtained even at the 6% optical feedback using the high-frequency modulation of 600 MHz. The threshold carrier density of the InGaN MQW-structure laser diodes was estimated to be 3/spl times/10/sup 19//cm/sup 3/ using a carrier lifetime of 1.8 ns.