Temperature-dependent rate equation model for high-speed vertical-cavity surface-emitting lasers

In recent years, seventeen billion of devices are Internet-connected worldwide, many of them coming from the IoT field. This number is going to increase years by years. The direct effect is a strong impact on the management of the data traffic that appears to be more and more centralized. Therefore, data center facilities have seen a huge boost in order to store and process such large amounts of data. The spread of cloud computing is another important factor contributing to the growth of the data center market. So in light of this, short-range communication plays a crucial role for intra-datacenter links. They require low cost, low power and high-speed transmitters; all requirements met by high-speed vertical-cavity surface-emitting lasers (VCSELs). The design and the optimization of a VCSEL is not an easy task since different, strongly coupled, physical phenomena take place in the whole device. A complete treatment would consider the solution of three main problems: electrical, thermal and optical. Many research groups have developed 3D multiphysical VCSEL models but they are time-consuming, unsuited for simulations of thousands of bits. It is of interest to have also simple and fast models for first-order analysis that at the same time obtain realistic simulation results. The scope of this thesis is to implement a fast rate equation model that takes into account thermal effect. Thermal characterization is important to have consistent simulated results since temperature affects significantly VCSELs performances. The proposed model is applied to a real device. The agreement with experimental results justifies the correctness of the implemented model.