Demonstration of high-performance 10.16 mu m quantum cascade distributed feedback lasers fabricated without epitaxial regrowth

We present measurement results on high-power low threshold quantum cascade distributed feedback lasers emitting infrared radiation at 10.16 mu m. A la teral current injection scheme allowed the use of a strongly coupled surfac e grating without metal coverage and epitaxial regrowth. Although this desi gn resulted in a simplified processing, the fabrication of high performance devices was demonstrated. The laser emitted 230 mW of pulsed power at 85 K , and 80 mW at room temperature. Threshold current densities of 1.85 kA/cm( 2) at 85 K and 5.4 kA/cm(2) at room temperature were observed. Since the sp ectrum showed single mode behavior for all temperatures and power levels of the operating range, this device will be ideal for optical sensor applicat ions. (C) 1999 American Institute of Physics. [S0003-6951(99)01931-2].