Design and analysis of O–S–C triple band wavelength division demultiplexer using cascaded MMI couplers

Abstract

Compact triple O–S–C band wavelength demultiplexer, which consists of series cascaded multimode interference (MMI) couplers has been carried out in this paper. The MMI coupler has been used to drop the wavelengths of 1510nm and 1550nm at bar port while the wavelength 1300nm into the cross port. Then another MMI coupler has been designed to separate the wavelength 1510nminto one port and wavelength 1550nm into another port. The triple wavelength demultiplexer function has been performed by choosing a suitable refractive index of the guiding region and geometrical parameters such as the width and length of MMI coupler. Numerical simulation with finite difference beam propagation method (BPM) has been utilized to design and optimize the operation of the proposed triple wavelength demultiplexer. The simulation results show that insertion losses of wavelength O, S and C, bands are 1.884dB, 1.452dB and 2.568dB, respectively, with isolations for each output waveguide ranging from 10dB to 28.72dB. The 3-dB bandwidth of insertion loss for 1300nm, 1510nm and 1550nm are 80nm, 20nm and 10nm, respectively.