AbstractInGaN multi-quantum-well (MQW) structure laser diodes with A10.14Ga0.86N/GaN modulation doped strained-layer superlattice cladding layers grown on an epitaxially laterally overgrown GaN substrate were demonstrated to have an estimated lifetime of more than 10,000 hours under continuous-wave operation at 20°C. Under operation at a high temperature of 50°C, the lifetime was longer than 1,000 hours. The activation energy of the lifetime was estimated to be 0.5 eV. With the operating current increasing above the threshold, a self-pulsation with a high frequency of 3.5 GHz was observed. The relative intensity noise (RIN) 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 LDs was estimated to be 3 × 1019/cm3 using a carrier lifetime of 1.8 ns.
Secure communication scheme using chaotic laser diodes subject to incoherent optical feedback and incoherent optical injection
