Evidence of gain enhancement in long wavelength strained quantum well laser diodes

Threshold current behaviour of InGaAs/InP quantum well laser diodes grown by atmospheric pressure MOCVD is measured and used as a means for determining characteristic modal gain constants. Structures incorporating 1.1% strain in the multiquantum well active region exhibit a threshold current density of 506 A/cm² at a cavity length of 1498 mu m, and are described by a characteristic modal gain constant that is 70% higher than in a similar device with 0.2% strain.