Quasi-cw high-power laser diode mini bars (λ=976 nm) with increased length of a resonator based on asymmetric heterostructures with a broadened waveguide

Abstract: Mini laser bars with 6-mm resonator length that include 5×100 μm emitters with a 25% fill factor are designed. It is shown that under pump current pulses of 1.0–9.5 ms duration (a 10 Hz repetition rate) and an amplitude peak value up to 50 A, a high emitting efficiency of 1.03 W·A_–1, corresponding to the power–current (P–I) characteristic, is maintained, with a maximum peak power being 48.4 W. The ability of mini laser diode bars to work in the quasi-cw regime at heatsink temperatures up to 100° with maintenance of the P–I curve linearity at a 25.7-W peak power and a 42-A pump current is demonstrated. A high uniformity in the distribution of radiation intensity in the far field with a divergence angle at half a maximum of 13° and 8° in the plane perpendicular and parallel to the heterostructure layers, respectively, is shown.

Keywords: diode laser bars, high-power semiconductor lasers, divergence in the perpendicular plane, quasi-cw regime.