Application Research Of Microring Resonator In Optical Communication Filtering

In dense wavelength division multiplexing(DWDM)system,the dense signals are broken into two groups with large channel spacing firstly in the demultiplexing process,the cost of the whole system can be reduced without upgrading the existing filter.The key device to realize this function of DWDM system is interleaver.In this paper,based on the analysis of the working principle of micro-ring resonator filters and Mach-Zehnder(M-Z)interferometer,the effects of essential parameter changes on the output characteristics(amplitude and phase property)have been deeply discussed.On the basis of the phase properties of micro-ring resonator filters,we proposed a nested ring resonator(NRR)which has a unique phase characteristic.Through our research,we found that the clever combination of NRR and M-Z interferometer can achieve wideband filtering.In this paper,we proposed a new bandpass filter and an interleaver that consists of MZI side-coupled with a NRR.The main works of this paper are:The influence on the output spectrum of single-coupled ring resonator and dual-coupled ring resonator were analysed theoretically by changing essential parameters,their phase properties and spectral properties were mainly studied.An NRR which has simple structure and unique phase characteristic has been designed with using the structure as the basis.The effects of essential parameter changes on the output waveforms of NRR have been analysed.We analysed the output characteristics of M-Z interferometer filter and micro-ring resonator assisted M-Z filter.Based on the coupled-mode theory,the output function of the nested ring resonator coupled to M-Z interferometer has been deduced.The output of the filter is simulated by using the output function,emphasis on the influences of micro-ring circumference,the inside and outside ring length ratio and coupling coefficient on the filter characteristics.According to different output ports,we discuss its application in DWDM system.The impact of key parameters on the performance of the filter,such as the bandwidth,center wavelength,ultra-narrow bandwidth,passband flatness,sidelobe depression and bandwidth ratio of the filter has been analyzed in this paper.According to design and optimize the parameters,we can get a better performance filter.Finally,the simulation experiment is carried out to realize the specific parameters of the device.The results of this study are of great significance to the application of ring resonator assisted M-Z filter.