Quasi-CW, High-Power, Extended-Cavity Laser Diode Microarrays (λ = 976 nm) Based on Asymmetric Heterostructures with an Ultrawide Waveguide

Abstract

We report the development of laser diode microarrays with a cavity length of 6 mm, which include emitting regions 5 × 100 μm in size with a fill factor of 25%. It is found that in the range of pump-current pulse durations of 1.0–9.5 ms (a repetition rate of 10 Hz) and a pump-current amplitude up to 50 A, a high lasing efficiency is maintained, corresponding to the slope of the light–current characteristic of 1.03 W/A, with a maximum peak power reaching 48.4 W. A possibility is demonstrated of the microarray operation in a quasi-CW regime with an increase in the heatsink temperature up to 100°C and with the linearity of the light–current characteristic at a power of 25.7 W and a pump current of 42 A. A high uniformity of the radiation intensity distribution in the far field is shown with a vertical divergence angle (at the FWHM level) of about 13° and a lateral divergence angle of about 8°.