Device deformation during low-frequency pulsed operation of high-power diode bars

Abstract

Thermal tuning rates of single emitters in “cm-bar” high-power diode laser arrays are analyzed. We find these tuning rates to consist of purely thermal and mechanical pressure contributions, of −0.48 and −0.08 meV(K)−1, respectively. We estimate the mechanical deformation such a device experiences during pulsed operation to be 0.07%, and then apply an adequate external force to single segments of cm bars. These single segments model the central emitters within the array. Effects that arise due to gradual aging, such as nonequilibrium carrier lifetime decrease, sheet carrier concentration increase, and defect concentration rise are monitored and analyzed over up to 2×106 deformation cycles. These experiments provide the basis for a type of accelerated aging experiment for device testing, especially of devices designed for low-frequency pulsed operation.