Abstract
We propose and numerically analyze a fiber-optic sensor based on a silica taper-assisted multiple polymer microspheres to realize high-sensitivity refractometric sensing due to the excitation of multi-beam interference and whispering-gallery modes (WGMs) in each microsphere. Up to 5 UV-cured adhesive microspheres are dripped in sequence on the 2 µm-diameter silica taper with the certain distances in between. Scattering and reflection of light in each microsphere enhance the multi-beam interference because of the emergence of high-order modes. Moreover, WGMs with certain resonant wavelengths are excited in the microspheres, further enhancing the transmission spectrum with high contrast and quality factor. Furthermore, irregular transmission spectrum corresponds to the large wavelength tuning range. Propagating light between the microspheres could be strongly affected by the environmental factor with the large transmission spectrum shift, therefore realizing the refractometric sensing with high sensitivity of 846 nm/RIU based on the taper-assisted 2-spheres sensor. Furthermore, another two microspheres are placed on both sides of 2-spheres sensor to form 4-spheres-loop sensor, re-collecting those large-angle scattering light with the enhancement of multi-beam interference and WGMs. Therefore, the sensitivity of 4-shperes-loop sensor is further improved to the maximum of 1296.3 nm/RIU.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
