Observation of lasing from Cr2+:CdTe and compositional effects in Cr2+-doped II-VI semiconductors.

We are engaged in a systematic study of the optical and laser properties of Cr²⁺-doped cadmium chalcogenides. Previously, we demonstrated quasi-continuous wave lasing from Cr²⁺-doped Cd_0.55Mn_0.45Te with slope efficiencies as high as 64% and a laser tuning range from 2,170–3,010 nm. In this paper, we report the first demonstration of lasing from Cr:CdTe at room temperature. Pulsed-laser operation was obtained with a free-running spectrum centered at 2,535 nm. The slope efficiency of the laser was low (∼1%) because of large parasitic losses at the laser wavelength. The spectroscopic properties of Cr:CdTe are favorable for laser applications because of a large emission cross section (∼2.5 × 10⁻¹⁸ cm²) and a high emission-quantum yield (∼88%). In addition, CdTe can easily incorporate Cr ions either through melt growth or diffusion doping. Along with our results on Cr²⁺:CdTe, we report on the optical properties of several other Cr²⁺-doped II-VI semiconductors (ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, Cd_0.9Zn_0.1Te, Cd_0.65Mg_0.35Te, Cd_0.85Mn_0.15Te, and Cd_0.55Mn_0.45Te) and compare them for applications as solid-state laser materials. [ABSTRACT FROM AUTHOR]