A micro optocoupler based on a microdisk laser and a photodetector with an active region based on quantum well-dots

We report on the possibility to detect laser emission of microdisk laser having diameter of 24 $\mu$m with an active region based on InGaAs/GaAs quantum well-dots using a waveguide photodiode (100 $\times$ 4000 $\mu$m) with a similar active region. A photocurrent of $\sim$10 $\mu$A was obtained under a continuous-wave laser operation, injection current of 20 mA and a distance between the facets of the microlaser and photodiode of about 100 $\mu$m. The photodiode's sensitivity was estimated to be $\sim$9 $\mu$A/10 $\mu$W.