High-frequency current-induced switching of higher order transverse modes in vertical cavity surface emitting lasers

Summary form only given. Electronically steerable laser diodes are of interest in many applications that require high speed beam steering. It is known that vertical cavity surface emitting lasers (VCSELs) can emit multiple higher-order transverse modes (HOTMs) due to spatial hole burning (SHB). A particular HOTM can be selected near threshold by appropriate injection current profiling. In the present work, current modulation of one and two HOTMs are studied. Alternate modulation of two orthogonal HOTMs can double the pulse repetition frequency obtained by modulating just one HOTM, without increasing injected current density levels. In this way, alternate high-speed beam steering in the VCSEL azimuthal direction is obtained, since associated far-field distributions approximately maintain the nearfield shape. In this work, a cylindrical weakly index guided VCSEL is considered. The model incorporates the spatial dependence of carrier and optical field profiles.