Spontaneous emission factor of oxidized vertical-cavity surface-emitting lasers from the measured below-threshold cavity loss

Abstract

A method to estimate the spontaneous emission factor beta is proposed and applied to the 780 nm oxidized vertical-cavity surface-emitting lasers. The proportionality of the measured cavity loss multiplied by optical power to injected current is used. Our results agree better with theoretical calculations than those of conventional light-current curve fitting. The spontaneous emission factor of 0.0021 is obtained for a 2-mu m-square device at room temperature. Since only the below-threshold information of cavity loss and output power are used in our method, the obtained beta values are independent of any complex and unexpected above-threshold effects such as thermally induced mode-size contraction, as they should be. (C) 1997 American Institute of Physics.