High average power first-order distributed feedback quantum cascade lasers

We present distributed feedback quantum cascade lasers at 965 cm(-1) with a high average optical output power at temperatures of up to 60 degreesC, At a duty cycle of 3%, the averaged maximal output power of a 55-mum wide and 1.5-mm-long device at -30 degreesC was 13.6 mW; at 60 degreesC, the device emitted 2 mW. Corresponding peak optical powers of 450 mW at - 30 degreesC and of 70 mW at 60 degreesC have been observed, Due to the lateral current injection, we achieved single-mode behavior in a slightly distorted zero-o rder lateral mode across the whole range of investigated temperatures and o utput powers. At room temperature, the threshold current density was on the order of 6.7 kA/cm(2); the characteristic temperature To was, due to tunin g of the Bragg resonance into the gain curve, rather high, namely 310K.