Distributed feedback Pb1−xSnxTe double-heterostructure lasers

Distributed feedback laser operation is demonstrated in stripe-geometry Pb1−xSnxTe double heterostructures grown by molecular-beam epitaxy. The grating of 1.1 μm periodicity operates in first order near 745 cm−1 (13.4 μm) under pulsed conditions in a limited range of heat-sink temperatuers (∼30–65 K) where both gain and the Bragg reflection condition can be achieved. The guide index ng≃6.1 is consistent with theoretical estimates. In Pb1−xSnxTe DH devices, by corrugating the surface after all epitaxy is completed, a large coupling coefficient for Bragg reflection can be achieved because the last confining layer can be made very thin and the grating aspect ratio large.