A novel method to enhance the robustness of the microcavity coupling system(MCS)is presented by encapsulating and solidifying the MCS with a low refractive index(RI)curable UV polymer.The encapsulating process is illustrated in detail for a typical microsphere with a radius of R about 240μm.Three differences of the resonant characteristics before and after the package are observed and analyzed.The first two differences refer to the enhancement of the coupling strength and the shift of the resonant spectrum to the longer wavelength,which are both mainly because of the microsphere surrounding RI variation.Another difference is the quality factor(Q-factor)which decreases from 7.8×10^(7)to 8.7×10^(6)after the package due to the polymer absorption.Moreover,rotation testing experiments have been carried out to verify the robustness of the package MCS.Experimental results demonstrate that the packaged MCR has much better robust performance than the un-package sample.The enhancement of the robustness greatly promotes the microcavity research from fundamental investigations to application fields.
YAN Ying-ZhanJI ZheYAN Shu-BinLIU JunXUE Chen-YangZHANG Wen-DougXIONG Ji-Jun
An ultra-small integrated photonic circuit has been proposed,which incorporates a high-quality-factor passive micro-ring resonator（MR） linked to a vertical grating coupler on a standard silicon-on-insulator（SOI） substrate.The experimental results demonstrate that the MR propagation loss is 0.532 dB/cm with a 10μm radius ring resonator,the intrinsic quality factor is as high as 202.000,the waveguide grating wavelength response curve is a 1 dB bandwidth of 40 nm at 1540 nm telecommunication wavelengths,and the measured fiber-to-fiber coupling loss is 10 dB.Furthermore,the resonator wavelength temperature dependence of the 450 nm wide micro-ring resonator is 54.1 pm/℃.Such vertical grating coupler and low loss MR-integrated components greatly promote a key element in biosensors and high-speed interconnect communication applications.
