Series resistance and its effect on the maximum output power of 1.5 μm strained-layer multiple-quantum-well ridge waveguide InGaAsP lasers

The series resistance of InGaAsP/InP multiple quantum well ridge waveguide laser diodes is investigated experimentally over a wide temperature range for both Fabry–Perot and distributed feedback type lasers. From the temperature dependence of the series resistance is found that it is defined mostly by the resistance of heterobarriers, although the semiconductor bulk resistance is also found to be a substantial part of ridge waveguide laser series resistance. The effect of the laser series resistance on other performance characteristics also investigated. The theoretically predicted strong correlation between the series resistance and laser maximum operating power is confirmed experimentally. The ways of reducing of series resistance are discussed.