High-order circuit-level thermal model of vertical-cavity surface-emitting lasers

Abstract

A high-order equivalent circuit model of vertical-cavity surface-emitting lasers (VCSEL) is introduced by virtue of the rate equations. This model accounts for both thermal and spatial dependences of VCSEL characteristics. A four-term Bessel-series expansion for the VCSEL carrier number is utilised to achieve good accuracy. A zero-order Laguerre–Gaussian beam is utilised for describing the photo distribution to simplify the computation. A general diode sub-circuit, instead of a complicated polynomial expression, is adopted to model the current–voltage relationship. This model is fast, accurate and scalable. Moreover, it can be readily used in SPICE-like circuit simulators. Numerical examples are included to validate this model and show that this model exhibits much improved accuracy than the previously published models.