Simulation Study And Analysis On Loss Of Waveguide Passive Ring Resonator

A optical waveguide passive ring resonator has become a basic component in integrated optics. It can be divided into the basic structure of filter and WDM(Wave division multiplexer). A passive ring resonator is widely used in many fields for their functionality and compactness. However,in the design of a passive ring resonator, bending of optical path is inevitable, bending of optical path can cause bending loss. For this reason, the main work of this paper is theoretical study about bending loss, to calculate and analyse the size of the bending loss. At the same time, the paper discuss the effect of ring resonator dimension and shape to the bending loss. The results show that the bending radius is bigger, smaller bending loss. There are several research areas:(1) Studies theoretical models of passive ring resonator. By coupled mode theory, it analyzes amplitude function in the resonator condition, through theoretical derivation about light wave amplitude in ring resonator, and reserches ring waveguide loss.and coupler loss of influence on the resonator finesse.(2) By improved effective index method, the paper contrasts the size of bending loss beweenx mnE mode andymnE mode and studies on the changes in the relationship between cross-sectional width, height of resonator and bending loss of resonator.(3) By coupled mode theory, analyzes coupling coefficient through theoretical derivation for coupled mode equation, On this basis, the relationship between coupling coefficient of rectangular straight waveguide and coupling spaceing is given.(4) The paper calculates the size of coupling length and coupling spacing,and results are given. At the same time do the simulation analysis about the relationship beween the bending loss and the length of cosine function, finding agreeable length to make bending loss smallest.In designing the size of waveguide cross-section,the paper research on single-mode transmission conditions of the rectangular waveguide,and does simulation study by MATLAB software.In the end, the paper conducted a comparative analysis and calculation of bending loss of different shapes of oval- racetrack ring resonator and round- racetrack ring resonator. The area value is given in which the bending loss is reduced to zero. and the precision of oval- racetrack ring resonator and round- racetrack ring resonator is given too.In the end,the resonance curve is drawn by simulation.