Vertical Cavity Surface Emitting Lasers (VCSELs) are a type of semiconductor laser diode. Unlike edge emitting laser diodes, VCSELs emit upwards and thus can be easily packaged as emitter arrays containing hundreds of emitters on a single chip. Often VCSELs are coupled with passive optics or scanning optics to generate very wide beams. Additionally, VCSELs are often used in pulsed mode. These factors make VCSEL test and measurement a challenging task. This article discusses VCSEL measurement solutions and how Ophir equipment can be used to get reliable power and beam profile data on VCSELs. Download the full paper for more information.