Continuous-wave emission from midinfrared IV–VI vertical-cavity surface-emitting lasers

Continuous-wave emission of two midinfrared PbSe vertical-cavity surface-emitting laser structures is presented. For both structures, optically pumped cw laser emission is observed at a wavelength of about 7.9 μm. Stimulated emission is found up to temperatures of 80 K. We achieved internal threshold pump intensities of down to 25 W/cm2, which is two orders of magnitude smaller than reported so far. The linewidth of the laser emission is only 18 μeV (0.9 nm) with a strong narrowing as compared to the linewidth of the cavity resonance. Continuous-wave output powers are up to 350 μW.