All optical asynchronous binary delta–sigma modulator

We present the first all optical delta–sigma modulator using a bistable device and a leaky integrator. In this paper, a novel tri-coupled ring geometry is utilized, resulting in resonance which is a building block for delta–sigma modulator. In each ring, the main active element is a semiconductor optical amplifier (SOA). The experimental result of the implemented setup is in a good agreement with our presented theory. Applying optical discrete components leads to a sampling rate of 660 kS/s. The higher frequency can be reached easily by using faster bistable devices and shorter loops.