Optical bistability in InGaN-based multisection laser diodes

Optical bistability is observed in cw-operating InGaN-based laser diodes including a saturable absorber (SA) section. The dependence of the light-current hysteresis on the SA section length and reverse bias ( V SA ) has been studied. An analytical approach is developed to estimate the carrier lifetime τ a in the SA section from the measurements of the hysteresis width, which leads to τ a = 1.9 ns at zero bias. τ a is found to decrease rapidly for higher reverse biases and a minimum of τ a = 0.4 ns is interpolated for flatband conditions. We explain the dependence of the carrier lifetime on V SA via the modification of the quantum-confined Stark effect.