Micro-disks embedded microring for optical filter

We propose a novel ultra compact structure of micro-disks embedded microring filter (MDEMR) and several parameters which impact the performance of MDEMR are analyzed. The filter is shown to exhibit much smaller size and better spectrum than traditional microring one. The number and radius of the inner disks are found to mainly influence the resonance frequency of the micro-disks, and the valley of transmittivity. The resonance between microring and micro-disks is decrease with increasing the gap between microring and micro-disks, which also leads to the extinction ratio improved significantly. The Q factor is found to be improved from 300 to 3000 with the gap increased from 0.2 μm to 0.4 μm, while the transmission peak affected slightly.