Reliability of 4.6-μm quantum cascade lasers under continuous-wave room-temperature operation

We report the life test results for 9 4.6-µm planar buried heterostructure quantum cascade lasers made of strain-balanced GaInAs/AlInAs/InP materials grown by metal organic vapor-phase epitaxy. No facet coating was deposited, and the devices were mounted on CuW submounts using AuSn solder. The aging condition is continuous wave operation at a heat-sink temperature of 22ºC with a constant current of 0.85A, corresponding to current densities of 4.7 and 2.7 kA/cm2, for lasers with widths of 4 and 7 µm, respectively. All lasers survived 5000 h aging, and most devices showed improved performance during the first 1000 h of aging.