Optical Control of Ring Modes Using Tandem Quasi-Stadium Laser Diodes

In order to demonstrate controlling directional emissions corresponding to the ring trajectory modes by using external optical injection, we fabricate the AlGaAs/GaAs single-quantum-well tandem quasi-stadium laser diodes consist of the front slave and the rear master laser diodes. The geometry of the laser cavities have been defined by using a lithography system and a reactive-ion-etching technique. The optical injection is performed from the master laser to the slave laser. The ring mode control with the optical injection is evaluated by far-field patterns for the output from the curved end mirror.