Design And Analysis Of Concentration Sensor Based On Microring Resonator

Microring resonator based on planar waveguide have a high quality factor and low loss. Silicon on insulator (SOI) is emerging as an important material in the field of integrated optics. Compared with other materials (such as silicon nitride, polymers), it has the advantages of low cost and simple fabrication process. Therefore, we have investigated the SOI-based on a microring resonator concentration sensors in this paper. The sensor exhibit remarkable features such as low-cost, small size, the potential for high volume production, hybrid integration with fluidic and electronic microsystems, as well as detective specific bio-chemical analytes. The main results are listed as follows:First, the wave optics theory of the slab waveguide is discussed based on the Maxwell equations. According to Marcatili’s model and the effective index method analyzes the mode characteristics of rectangular waveguide. Then the electric field distribution of slot waveguides are computed and the coupling mechanism of the slot waveguides are theoretically analyzed.Second, the key parameters of a microring resonator are derived and established theoretical model. Using the finite difference time domain (FDTD) method and beam propagation method (BPM) in the microring resonator is numerically simulated. We studied the transport properties and coupling efficiency of microring resonator. The simulation results provde theory for design and application of SOI microring resonator-based concentration sensors provide theory basis.The solution concentration sensor based on microring resonator is designed in finally. Different concentrations of ethylene glycol solution can change the effective refractive index of waveguidge, then the resonance wavelength of microring resonator are accordingly changed. The resonance wavelength of microring is calculated by Matlab. Using the finite difference time domain method simulates power spectrum of microring in different concentration and calculates the resonance wavelength of microring. They are consistent with theoretical calculation result and numerical simulation result. This result show that the sensor is feasible. Furthermore, a sensitivity of490.2nm/RIU was found in the concentration of ethylene glycol solution ranging from30%to95%. A limit of detection of4.08×10-5RIU was determined.