Carrier transport effects in 1.3 μm MQW InGaAsP laser design

We have investigated the influence of the barrier height on the performance of InGaAsP MQW lasers emitting at 1.3 μm via simulations, direct hole transport time measurements and laser evaluation. The results from the simulation showed that too high barriers will result in an increase in hole and electron concentrations at the p-side of the MQW. This leads to a severe increase in the Auger recombination rate. The measured hole transport time is clearly dependent on the barrier height in the MQW. MOVPE-fabricated lasers with up to twelve periods and optimised barrier heights showed internal efficiency values above 95%, internal losses below 10 cm^-1, threshold densities as low as 60 Acm^-2/well and T₀ values as high as 79 K in the temperature range 20-80°C. Our conclusion is that attention should be given to the valence band carrier distribution when designing for low threshold, high optical output MQW lasers aimed for elevated temperature operation