Recent advances in semiconductor lasers

The threshold current for GaAs Diode lasers has been reduced at the higher temperatures and has led to higher external quantum efficiencies at these temperatures. Using new materials, laser action has been extended further in the infrared and has reached the
8-14-\mu
atmospheric window. Diode lasers in which the laser action occurs in the bulk of the semiconductor are reported. Semiconductor lasers have been pumped with an electron beam.