Research On The Waveguides Based On The Grating Assisted Coupler For Wavelength Division Multiplexing Method For Optofluidic Biosensing

Whispering gallery mode resonator based optical microfluidic sensor is alabel-free, high sensitivity biosensing technology, because these sensors have a veryhigh quality factor resonators and sensing sensitivity, thus becoming a popular fieldof study biosensing subject. To make light of microfluidic biosensors can achieve highthroughput sensor detection, this paper carried out a study of the optical waveguidegrating coupler microfluidic sensor multiplexing method based on usingcoupled-mode theory analysis of waveguide grating coupler auxiliary transmission,the establishment of a simulation model ARROW waveguides and coupled withmicrotubule structure and use FullWAVE software for the simulation analysis, basedon the theoretical analysis simulation experiment system built on the performance ofthe secondary grating couplers are explored; addition, this article method to verify theoptical field distribution on microtubules whispering gallery mode resonator fordifferent radial mode sensor sensitivity by changing the angle of the incident light andthe experimental concentrations of ethanol solution, using a prism coupler from boththeoretical and experimental analysis stimulate radial modes have different sensingsensitivity of the micro-tube. The main work is completed as follows:1) Based on the coupled mode theory microtubules cavity were analyzed toderive the microtubule cavity transmittance; whispering gallery mode resonator andcavity EMF studies the distribution of microtubules explored under different radialmodes of microtubule optical field distribution on the sensor sensitivity.2) Introduced the concept of the grating coupler and auxiliary ARROWwaveguides, the first use of a unified analysis of the coupled-mode equationsauxiliary grating wavelength selective coupler principle, then introduced theARROW waveguide-type characteristics and important parameters, elaborated onthis basis, based on auxiliary ARROW waveguide grating coupler, and the use of theauxiliary coupler module FullWAVE simulation analysis, analyzes the simulationmethod using the double-microtubule complex structure, the effect of the gratingperiod, the core layer thickness and other parameters of the coupling effect, as usedin optical microfluidic sensor based multiplexing ARROW waveguide grating assistedcoupler provides a theoretical basis. 3) The use of different types of coupling are excited at the thick and thethin-walled microtubules microtubules in the whispering gallery mode resonator,showing the difference between the two coupling methods, and by influencing thesensitivity of the relationship between model and experiments were verified forfollow-up experiments provide theoretical guidance; build a grating couplingmicrotubule system, using wet etching and fused taper manner required for theexperiment were prepared with the micro-capillary fiber grating by couplingexperiments on microtubule-based waveguide grating coupling sensor multiplexingconducted a preliminary exploration, laying the foundation for future in-depthresearch.