Anti-symmetric quadruple ring resonator based optical filter

Vernier principle based anti-symmetric optical ring resonator made of glass silica has been used in this work for obtaining wider value of free spectral range (FSR). Here delay line signal processing in Z-domain and Mason's Rule have been used for analyzing this quadruple anti-symmetric ring resonator (QARR). Free spectral range (FSR) of 6.6 THz is obtained in this case which is comparable with the experimentally obtained result from the similar kind of architecture using other method of analysis. Besides obtaining wider FSR, this work presents significant improvement in terms of cross-talk which is less than 77 dB without compromising resonant characteristics. Group delays, dispersion characteristics and finesse for this quadruple optical ring resonator have also been investigated. This work is also, a new approach to analyze multiple ring resonator-based devices made of symmetrical ring length using Vernier principle. (C) 2015 Elsevier GmbH. All rights reserved.