Analysis of silicon waveguide structure for realization of optical MUX/DEMUX circuit: An application of silicon photonics

Structure, operation and simulation of optical multiplexer and demultiplexer using silicon waveguide structure is discussed in this paper. Here silicon waveguide structure is realized by eighty three layers of waveguide in such way that it consists of 42 layer of silicon and 41 layer of air materials in an alternate manner. Here both reflection and absorption losses are considered to realize MUX/DEMUX. Simulation for reflectance is done using plane wave expansion method, where absorption loss is found zero for all wavelengths. Simulation results revealed that number of layers of waveguide, thickness of odd and even layers; structure period and length play an important role to design optical multiplexer and demultiplexer circuit. Present simulation result showed that waveguide having thickness of odd layer (silicon) 1180 nm and even layer (air) 200 nm, allows wavelength 850 nm and reflects wavelength 1310 nm and 1550 nm. Similarly, structure having thickness, 180 nm of odd layer (silicon) and 300 nm of even layer allows wavelength 1310 nm and reflects to both 850 nm and 1550 nm. And thickness of 80 nm (odd) and 180 nm (even) allows 1550 nm and reflects both 850 nm and 1310 nm. Apart from this it is also seen that same waveguide structure having thickness of odd layers, 1 nm and even layers, 999 nm allows all wavelengths (850 nm, 1310 nm and 1550 nm).