Optically controlled surface emitting lasers

Summary form only give. SELs (surface emitting lasers) whose output power can be modulated by an external light source are reported. The vertically integrated device used is a heterojunction phototransistor (HPT) in series with a SEL so that the amplified photocurrent of the HPT drives the SEL. It is critical that this current exceed the threshold current of the laser with reasonable incident power. Both a linear mode of operation and a bistable mode are found at different voltage ranges. Even though the device has not yet been optimized, an overall optical power gain is observed.<<ETX>>