Strong optical coupling between semiconductor microdisk lasers: From whispering gallery modes to collective modes

In the present paper, we investigate a special type of optical coupling between two electrically pumped semiconductor whispering gallery mode lasers. We fabricate microdisk lasers with a conjunction between the laser cavities, making the coupling stronger. Our experimental results combined with numerical calculations demonstrate a variety of mode families that exist in such systems. Furthermore, we confirm the generation of resonance modes that exist only under simultaneous pumping conditions. These modes are attributed to the collective mode family, which can lead to a single mode operation.