Design and Simulation of All Optical Frequency Shift Keying Demodulator by Using Photonic Crystal based Resonant Cavities

Using all optical devices for implementing all optical communication networks is very important. By using all optical frequency shift keying demodulators one can generate binary codes from the frequency of optical waves. In this paper a novel structure has been proposed for designing photonic crystal based all optical frequency shift keying demodulator. Three resonant cavities with different resonant modes were used for the frequency selecting section. In order to separate three different resonant modes, the radius of the defect rods used inside the cavities was chosen with different size. The simulation results show the proposed structure can generate four binary codes according to the frequency of the input optical waves. Therefore the final structure can work as an all optical frequency shift keying demodulator which can generate 00, 01, 10 and 11 codes at the output ports. The maximum delay time of the proposed structure is 4 ps.