Multi-photon pumping in a large band gap semiconductor laser

Researchers examined the effects of using an infrared short pulse laser as a multi-photon pump to create population inversion in a large band gap semiconductor. The laser field creates electron-hole plasma, but the power density of the laser has to be high to create coherent recombination at ultraviolet wavelength, and the method induces only short pulses of coherent radiation. However, possible applications would be the production of millimeter waves or the operation of fast switches.