Double heterostructure Pb1-<i>x</i>Sn<i>x</i> Te–PbTe lasers with cw operation at 77 K

Abstract

Diode lasers that operate cw at 77 K have been made from a Pb0.88Sn0.12 Te–PbTe double heterostructure grown by liquid phase epitaxy. Junction diffusion during growth has been prevented by the use of Tl-doped PbTe substrates. The wavelength emitted in cw operation has been temperature tuned from 10.5 μm at 12 K to less than 8.2 μm at 80 K, a range of nearly 280 cm−1. The cw threshold current density increases from 1.6 × 103 A/cm2 at 12 K to 4.2 × 103 A/cm2 at 77 K. The measured cw power is 10 mW in four modes at 12 K (1.8 × 104 A/cm2) and 1.2 mW in a single mode at 77 K (7.5 × 103 A/cm2).