ANALYSIS OF 6-NM ALGAAS SQW LOW-CONFINEMENT LASER STRUCTURES FOR VERYHIGH-POWER OPERATION

This paper reports experimental results on single quantum-well separat e confinement heterostructures (SQW SCH) with low-confinement factor, designed for very high-power operation, The maximum power output for A R/HR coated 3-mm-long devices, measured in very short pulsed condition s (100 ns/1 kHz), from 10-mu m-wide stripes was as high as 6.4 W befor e catastrophical optical degradation, If scaled to continuous-wave (CW ) conditions, this value would be 800-1100 mW, which would mean a fact or of 2-2.7 times more than reported for the best devices with normal design for threshold minimization, The absorption coefficient for the symmetrical structure is as low as 1.1 cm(-1), in spite of the low tra pping efficiency of carriers in the quantum well (QW), The maximum dif ferential efficiency is 40% (both faces, uncoated devices) for symmetr ical structure and 33% for the asymmetrical one (all measurements in p ulsed conditions), Threshold current densities were 800 A/cm(2) for 5- mm-long devices in the symmetrical case and 2200 A/cm(2) in the asymme trical one, The effects of inefficient carrier trapping in the QW on t he threshold current densities and differential efficiency are discuss ed.