Temperature analysis of threshold current in infrared vertical-cavity surfaceemitting lasers

Abstract—The temperature dependence of threshold current th in vertical-cavity surface-emitting lasers (VCSELs) can be ap-proximated by the equation th min 2, where min is the temperature of lowest th and are parameters, and temperature is. We compare the temperature dependence of threshold current in VCSELs with GaAs, InGaAs, and strain compensated InGaAs–GaAsP quantum wells. From our analysis we find the coefficient is related to the gain properties of the quantum well, and is shown to serve as a benchmark for the VCSEL temperature sensitivity. The incorporation of strain-com-pensated high-barrier GaAsP layers in the active region of 980-nm VCSELs is demonstrated to reduce the threshold dependence on temperature. Index Terms—Diode lasers, temperature analysis, threshold cur-rent, vertical-cavity surface-emitting lasers (VCSELs). I