Feature

Semiconductor quantum wire lasers

E. Kapon

The performance of semiconductor lasers has been improved by the use of quantum confinement in one dimension. In these conventional quantum well (QWL) lasers, the charge carriers recombine and emit light in extremely thin (usually less than 100 A) layers of a lower band gap semiconductor such as GaAs cladded by a higher band gap barrier compound, e.g., AlGaAs. The quantum confinement of carriers in the direction normal to the QWL plane gives rise to discrete energy levels, which effectively narrows the spectral profile of the optical gain. This, in turn, leads to lower threshold currents, higher modulation bandwidths, narrower spectral linewidths, and reduced temperature sensitivity.