Micro-displacement detection of nanofluidic fluorescent particles based on waveguide-concentric ring resonator model

Abstract

Dynamic tracking and detection of nanoparticles in micro-nanofluids have always been a challenging and demanding work. In this work, we propose a waveguide-concentric ring resonator integrated optical platform, based on the waveguide-concentric ring resonator. The change of the fluorescence power intensity output by the cavity coupling structure is used to realize the micro-displacement detection of nanoparticles in the micro-nano fluid. Because the ring micro-resonator has the characteristics of high Q and is sensitivity to the surrounding environment, the sensitivity of the device is greatly improved. The finite-difference time domain method has been carried out on the study of parameters such as the polarization state of the fluorescence and the distance between the two ring resonators. The double-peak changes of the fluorescence output power can be used to detect the displacement of the nanoparticles with high precision. Based on the synchronization of the double-peak changes, the detection can reduce the influence of environmental noise and improve the detection accuracy. The numerical simulation results also confirm that this method can measure the micro-displacement of nanoparticles in nanofluids in the range of 0-1000nmproviding new directions and ideas.