Assessing the Performance of Visible (665 nm) Vertical Cavity Surface Emitting Lasers Using High Pressure and Low Temperature Techniques

Abstract

The effects of carrier leakage and gain-cavity alignment on the temperature dependence of the threshold current (I th ) in visible vertical cavity surface emitting lasers (VCSELs) are investigated. In order to assess the two effects and the degree to which they couple we have performed pressure and temperature experiments on VCSELs and their equivalent edge emitting lasers (EEL). We have established that the peak of the gain moves with pressure at a rate of 72 meV GPa -1 more than three times the rate of 22 meV GPa -1 for the cavity mode. However, we show that over the temperature operating range carrier leakage into the indirect X-minima is the major contributor to an increased I th , nevertheless optimised gain-cavity alignment can lead to more stable operation.