High peak power mini-array quantum cascade lasers operating in pulsed mode

Abstract Broad area quantum cascade lasers (BA QCLs) have significant applications in many areas, but suffer from demanding pulse operating conditions and poor beam quality due to heat accumulation and generation of high order modes. A structure of mini-array is adopted to improve the heat dissipation capacity and beam quality of BA QCLs. The active region is etched to form a multi-emitter and the channels are filled with InP:Fe, which acts as a lateral heat dissipation channel to improve the lateral heat dissipation efficiency. A device with λ ∼ 4.8 μm, a peak output power of 122 W at 1.2% duty cycle with a pulse of 1.5 μs is obtained in room temperature, with far-field single-lobed distribution. This result allows BA QCLs to obtain high peak power at wider pump pulse widths and higher duty cycle conditions, promotes the application of the mid-infrared laser operating in pulsed mode in the field of standoff photoacoustic chemical detection, space optical communication, and so on.