Liquid-core optical ring-resonator sensors

Abstract

We have demonstrated a novel sensor architecture based on a liquid-core optical ring-resonator (LCORR) in which a fused silica capillary is utilized to carry the aqueous sample and to act as the ring resonator. The wall thickness of the LCORR is controlled to a few micrometers to expose the whispering gallery mode to the aqueous core. Optical characterization with a water-ethanol mixture shows that the spectral sensitivity of the LCORR sensor is approximately 2.6 nm per refractive index unit. A model based on Mie theory is established to explain the experimental results. The LCORR takes advantage of the high sensitivity, small footprint, and low sample consumption with the ring resonator, as well as the efficient fluidic sample delivery with the capillary, and will open an avenue to future multiplexed sensor array development.

Flow-enhanced transient response in whispering gallery mode biosensors

“…Both the time to achieve a given level of binding during an experiment and the amount of valuable sample required can be reduced by using convection. Some WGM sensor embodiments, like the liquid-core optofluidic ring resonator, 6 have their own integrated flow systems. Microfluidic flow cells 7 have also emerged as a popular delivery system due to their small volumes and ease of fabrication, but integration into WGM sensing systems has, understandably, received limited attention in the face of the pressing need for further characterization of basic device performance.…”

Organic distributed feedback laser for label-free biosensing of ErbB2 protein biomarker

“…While detection resolution can be substantially improved through the use of high M a n u s c r i p t Q-factor passive resonators, it is generally at a cost of a decrease of the sensitivity and the dynamic range of the system. Only a few examples of passive resonators have achieved high Q-factor and high sensitivity simultaneously [4]. In addition, the implementation of high Q-factor optical resonators typically requires high precision alignment for evanescent light in/out coupling, providing potential limits to their practical application.…”

Refractometric Sensing of Heavy Oils in Fluorescent Core Microcapillaries

“…In these devices, referred to as Liquid-Core Optical Ring Resonators (LCORR) [14], the analyte fluid is pumped through the capillary channel while light from a tuneable laser is coupled evanescently through a fiber taper into the capillary wall. The wall of the capillary acts as a cylindrical cavity inside which high-quality-factor (high-Q) optical resonances can develop.…”