Performance analysis of pentuple asymmetrical optical microring resonator as optical filter considering fabrication tolerances

In this paper, a pentuple asymmetrical optical micro ring resonator (PAOMRR) is proposed for the application as an optical filter. The proposed PAOMRR comprises five asymmetrical microring and four linear waveguides which can be used for multiple input and multiple output ports. The input signal can be fed from any port and the remaining three ports can be selected as output ports. In other words, the proposed configuration can act as a 1X3 input–output filter where each output port is capable of producing a unique free spectral range (FSR). The reported FSR is significantly improved which can be great advantage in the field of communication. Mathematical modelling of the proposed PAOMRR is done in Z-domain using delay line signal processing methodology. The Frequency response of the proposed PAOMRR is simulated in MATLAB software and the electromagnetic field propagation inside the waveguide is studied using OptiFDTD software. Several characteristics such as group delay, dispersion, finesse as well as Q-factor is evaluated to check the efficacy of PAOMRR. To encounter the fabrication tolerance issue, an attempt is made to study the variation in response whenever there is a change in the position of microrings. In this paper, the orientations of outer diametrically opposite microrings are rotated by 45 degree in clockwise as well as anti-clockwise directions. The FSR and Q-factor values are analysed for the mentioned scenarios and it is found that the proposed PAOMRR is robust in handling any kind of fabrication deformities.