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

Abstract

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) 1180nm and even layer (air) 200nm, allows wavelength 850nm and reflects wavelength 1310nm and 1550nm. Similarly, structure having thickness, 180nm of odd layer (silicon) and 300nm of even layer allows wavelength 1310nm and reflects to both 850nm and 1550nm. And thickness of 80nm (odd) and 180nm (even) allows 1550nm and reflects both 850nm and 1310nm. Apart from this it is also seen that same waveguide structure having thickness of odd layers, 1nm and even layers, 999nm allows all wavelengths (850nm, 1310nm and 1550nm).