Abstract
We report a direct method to observe higher-azimuthal-order whispering-gallery-like modes in vertical cavity surface emitting lasers (VCSELs) at room temperature. Instead of introducing any defect mode, we show that suppression of lower-order cavity modes can be achieved by destroying vertical reflectors with a surface micro-structure. Perfect higher-order modes with an azimuthal number as large as 41 are observed in experiments through collecting near-field radiation patterns, as well as in numerical simulations. © 2009 Springer-Verlag.