Anisotropic Transverse Confinement Design for Electrically Pumped 850 nm VCSELs Tuned by an Intra Cavity Liquid-Crystal Cell IEEE Journal of Selected Topics in Quantum Electronics

Relying on preliminary experiments, in this work we design a tunable 850 nm laser based on a hybrid combination of a liquid crystal micro-cell with nanoimprinted grating and an electrically-pumped GaAs half-VCSEL. The optical design is challenging due to the inherent tolerances of this hybrid technology, the presence of metals in the cavity and the need for single fundamental extraordinary mode emission over the whole tuning range. To ensure proper operation, we introduce for the first time the new concept of anisotropic transverse confinement design. The overall performance is verified by our multiphysics VCSEL suite. Beyond tuning features, we predict side mode suppression ratio and optical power under all working conditions, comparing the performance of liquid crystals with different clearing temperatures. The results qualifies these lasers as viable tunable sources with interesting performance and complementary features compared to other technologies.