The anatomy of the Gunn laser

Abstract

A monopolar GaAs Fabry-Ṕrot cavity laser based on the Gunn effect is studied both experimentally and theoretically. The light emission occurs via the band-to-band recombination of impact-ionized excess carriers in the propagating space-charge (Gunn) domains. Electroluminescence spectrum from the cleaved end-facet emission of devices with Ga1-x Alx As (x=0.32) waveguides shows clearly a preferential mode at a wavelength around 840 nm at T=95 K. The threshold laser gain is assessed by using an impact ionization coefficient resulting from excess carriers inside the high-field domain. © 2008 American Institute of Physics.