Reduction in the rate of increase of spontaneous emission from double-heterostructure injection lasers at threshold

An abrupt reduction in the rate of growth of the spontaneous emission has been observed to occur at the lasing threshold of stripe-geometry double-heterostructure injection lasers. The observations are contrary to a previously published result of Sommers and imply that increases in the quasi-Fermi level separation with current are significantly reduced at the lasing threshold in agreement with present theoretical predictions.