All optical FSK demodulator using PhC-based ring resonators

For generating digital codes based on the frequency of input signal we need frequency shift keying demodulators. Optical demodulators are required for optical communication networks. In this paper we are going to design and propose a new structure for implementing all optical frequency shift keying demodulator. The proposed structure was designed using four resonant rings. Finite difference time domain method was used for simulating the propose structure. The simulation results show that when the frequency of input signal is 193.5 THz, 194 THz, 194.5 THz and 195 THz the proposed structure can generate 00, 01, 10 and 11 code at the output ports respectively. The maximum delay time of the proposed structure is 2 ps.