Holographic fabricated continuous wave operation of distributed feedback quantum cascade lasers atλ8.5μm

The fabrication and characterization of distributed feedback(DFB) quantum cascade lasers emitting atλ&asyum;8.5μm are reported. The first-order DFB grating structure was defined using the holographic lithography technique. Reliable dynamic single-mode emission with a side-mode suppression ratio of20 dB and a tuning coefficient of-0.277 cm-1/K from93 to210 K is obtained in continuous wave mode by using high-reflectivity coating on the rear facet. The output power is over100 mW at a temperature of80 K.?2011 Chinese Institute of Electronics.