High power and high efficiency 1060 nm semiconductor laser mini-bar with multi-active regions

Abstract

Aiming at the urgent demand of small volume, high efficiency and high power laser source in the field of laser ranging, we proposed a multi-active-regions mini-bar (MAMB) structure of semiconductor laser diodes, in which multi-active regions (or sub-LDs) are cascaded by reverse-biased tunnel junctions (TJs) transversely, meanwhile, several sub-cells composed of sub-LDs form mini-bar laterally. The entire structure was epitaxially grown on GaAs substrate by MOCVD. In order to minimize the additional series resistance introduced by the tunnel junction, InGaAs double quantum wells (DQWs) TJ is adopted. To increase the COMD level, each sub-LD uses an AlGaAs asymmetric large optical cavity, in which the active region is a compressive strained InGaAs DQWs. After the standard chip post-process, the MAMB was fabricated with the ridge-shaped sub-cells, which has a strip width of 200μm and cavity length of 1mm. The MAMB was then soldered on C-mount and mounted on TO3 to test at room temperature with a frequency of 20 Hz and a pulse width of 20 μs. The output power of a MAMB with 3 active regions and 3 sub-cells reaches 47.76 W (28 A), corresponding to a slope efficiency of 2.02 W/A, and the peak wavelength is 1060.6 nm. The results show that the MAMB structure could effectively improve the output power and reduce its volume.