THERMAL COUPLING AND LENSING IN ARRAYS OF VERTICAL CAVITY SURFACE EMITTING LASERS

The operating temperature of optoelectronic devices is the factor that most limits their performance and efficiency. In this thesis, we present research that focuses on investigating thermal behavior of operating vertical cavity surface emitting lasers (VCSELs) and VCSEL arrays. A variety of thermal effects are known to influence the performance of VCSELs and therefore, the goal of this research is to better understand how temperature affects the operation of these devices. Previously, a variety of techniques have been used to measure the temperature of VCSELs. These techniques tend to be bulk measurements that lack sufficient spatial and thermal resolution, cannot be used on light emitting surfaces, and/or are not able to simultaneously measure the temperature at very different length scales across a VCSEL or VCSEL array. Instead, we use thermoreflectance microscopy to obtain two dimensional, high spatial (250nm) and temperature (10 mK) resolution images of the surface temperature o