Pseudo-high-order-mode in vertical-cavity surface-emitting lasers (VCSELs)

Abstract

We built a test system to pick up the pattern of light beam from the VCSELs and the EL spectrum simultaneously in order to study the mode behavior when the current applied on the device increased. As a result, we observed that the light spots from the VCSEL seemd to be high-order-mode while its EL spectrum included more than one peak wavelength. Comparing it with the high-order-mode case that we met and defined in VCSELs before, we considered that the mode we observed this time was different from the true high-order-mode in essence. We named it as pseudohigh-order-mode and gave the explanation.