ABSTRACT
The group-IV-VI materials represented by PbTe, PbSe, PbS, or PbSnTe are narrow-gap semiconductors with NaCl-type crystal structure. The first laser operation of a group-IV-VI semiconductor was reported in 1964. The laser structure of the first generation was a diffused p-n junction diode laser, which operated easily at low temperatures. After the middle of 1980s, cladding layer materials using rare earth and alkali earth as alloy compounds were studied using molecular beam epitaxy and hot wall epitaxy. Due to the high Auger recombination rate in III-V compounds, the maximum operating temperature of III-V lasers significantly decreases with the wavelength, and IV-VI lasers have a relatively high operating temperature above 4 μm compared with the III-V materials.
