Theoretical investigation of static and dynamic characteristics of vertical-cavity surface-emitting lasers with incorporated two-dimensional photonic crystals

Abstract

A dynamical model of oxide-confined Vertical-Cavity Surface-Emitting Lasers (VCSELs) with two-dimensional photonic crystals (PCs) incorporated within them so called PC-VCSELs is presented and used to optimise designs for high-power single-mode operation. Three PC-VCSEL designs are considered: (I) with holes in the top DBRs, (II) with PC holes situated between their DBRs and (III) with PC holes etched through the entire VCSEL. A simulated design for a PC-VCSEL of type (I) with holes of d = 2 μm diameter, a = 4 μm lattice constant (d/a = 0.5) and 2.2 μm depth was found to improve the single mode behaviour but not enough to establish single mode behaviour for large apertures. The modulation behaviour was not degraded by the PC. Simulations of type (II) and (III) PC-VCSELs, with the same parameters, have shown multimode operation and degraded modulation properties. Simulations of PC-VCSELs of type (III) with holes of d = 0.2 μm diameter and a = 0.4 μm lattice constant (d/a = 0.5) have shown improved modulation properties and enhanced single mode power for small apertures. In simulation, PC-VCSELs incorporating multiple PC-defects have shown order of magnitude increases in the single mode output power. However, the modulation properties of these VCSELs show degradation due to gain saturation and hopping of the optical modes localized within the PC defects.