Measurement of spontaneous emission factor for 850 nm gain-guided vertical-cavity surface-emitting lasers

Abstract

Using a method based on the measurement of below-threshold cavity loss and optical power, we experimentally determine the spontaneous emission factor of 850 nm gain-guided vertical-cavity surface-emitting lasers. Since om method needs only below-threshold information, we can avoid complex problems concerning above-threshold effects and obtain more reliable results. It is also pointed out that the typical L-I curve-fitting method results in unreliable estimation of the spontaneous emission factor. The values of spontaneous emission factors obtained are 6.6, 4.1, and 2.4 x 10(-4) for 10-, 15-, and 20-mu m-diameter circular aperture VCSELs, respectively.