Optically Pumped In1−xGax P Platelet Lasers from the Infrared to the Yellow (8900−5800 Å, 77°K)

The laser operation (77°K) of optically pumped thin platelets of In1−xGaxP over the composition range x=0–0.59 (8900−5800°A) is demonstrated. The samples are prepared from material grown at constant temperature (900–1000°C) from In solution with source InP and GaP introduced at slightly higher temperature. The dependence of the laser photon energy upon composition agrees well with the Γ−χ curves of Lorenz and Onton and confirms the belief that the direct-indirect transition is at x∼0.74. In addition, unique spectral data on In1−x Gax P (x=0.27) are presented that show the mode development from spontaneous to high-level stimulated emission.