Study on the dominant mechanisms for the temperature sensitivity of threshold current in 1.3-μm InP-based strained-layer quantum-well lasers

Abstract

We study the basic physical mechanisms determining the temperature dependence of the threshold current (I/sub th/) of InP-based strained-layer (SL) quantum-well (QW) lasers emitting at a wavelength of 1.3 /spl mu/m. We show that I/sub th/ exhibits a different temperature dependence above and below a critical temperature T/sub c/. It is indicated that T/sub c/ is the maximum temperature below which the threshold gain exhibits a linear relationship with temperature. We demonstrate that below T/sub c/ the Auger recombination current dominates the temperature dependence of I/sub th/. On the other hand, above T/sub c/ a significant increase in both the internal loss and radiative recombination current in the separate-confinement-heterostructure region, which is mainly due to electrostatic band-profile deformation, is found to play a major role in determining the temperature sensitivity of I/sub th/. On the basis of the comparison between the theoretical analysis and the experimental results, we conclude that the temperature dependence of the threshold current in 1.3-/spl mu/m InP-based SL-QW lasers is dominated by different mechanisms above and below T/sub c/.