Extrinsic dynamics and Equivalent Circuit Modeling of High-Speed VCSELs

Abstract

To establish highly performing vertical cavity surface-emitting lasers (VCSELs), it is essential to have an adequate understanding of the intrinsic laser dynamics of these devices. However, this is done while bearing in mind that extrinsic parasitic elements in VCSELs play an important role in limiting the intrinsic modulation bandwidth. In this paper, we analyse different electrical parasitic equivalent circuit models in the aim of comparing them and selecting the one that can best describe and represent the physical properties of our high-performance VCSELs. Through measuring the microwave reflection coefficient $\mathrm{S}_{11}(\mathrm{f})$ and fitting it into the calculated counterpart from the equivalent-circuit impedance model, the parasitic components of the equivalent circuit model are extracted.