A behavioral approach to model thermal sensitivity of semiconductor lasers

A new method is proposed in this paper to model the effects of temperature on the steady state and large signal response of single mode edge emitting semiconductor laser. Traditionally, a separate thermal rate equation, in conjunction with the laser rate equation model is used to describe the thermal behavior [IEEE J. Quant. Electron., 31(10) (1995); J. Lightwave Technol., 17(9) (1999)] or, temperature dependence of the rate equation parameters is explicitly defined through their respective characteristic temperatures to model thermal behavior [IEEE Proc. J., 140(4) (1993); IEEE J. Quant. Electron., 4 (1968) 119; IEEE Photon. Technol. Lett., 1 (1989) 356]. However, these methods introduce a number of additional parameters that necessitate new measurements and rigorous numerical computations for their determination and impart more complexity to the model. In the work presented here, a new thermal threshold is defined for the external laser slope efficiency together with an output feedback function obtained through the rate equations-time dynamics. This inherently introduce the dominant thermal mechanisms into the model with the parameters extracted from steady state measurements in a self-consistent manner, providing considerable reduction in computation complexity. The resulting modified rate equations also account for high power gain saturation effects, which is otherwise only possible through higher-level (1D-3D) modeling methods. Measured results from two commercial single mode lasers have shown excellent conformance with simulations, using this approach.