Evanescent field refractometry in planar optical fiber

Diamond ring fiber for evanescent field exposure.

Diamond Ring Fiber (DRF) is proposed to allow a high percentage of evanescent field exposure while maintaining low confinement loss. It provides a long and protected medium for light-matter interaction and large cavities to ease the infiltration of sensing elements. DRFs with different waveguide parameters have been analyzed theoretically and fabricated using a stack-and-draw fiber drawing tech...

Evanescent field absorption in a passive optical fiber resonator using continuous-wave cavity ring-down spectroscopy

We combine the sensitivity advantages of cavity ring-down spectroscopy (CRDS) with the versatility of optical fiber sensing technology in a spatially extended passive fiber ring resonator constructed of common telecommunications components. The resonator is characterized with both pulsed and continuous-wave diode laser excitation, and it is shown to be a practical device for direct measurement ...

A Novel Approach to Evaluate the Sensitivities of the Optical Fiber Evanescent Field Sensors

A Silver Nanoparticle-Modified Evanescent Field Optical Fiber Sensor for Methylene Blue Detection

A silver nanoparticle-modified evanescent field optical fiber sensor based on a MEMS microchannel chip has been successfully fabricated. Experimental results show that the sensor response decreases linearly with increasing concentration of analyte. Over a range of methylene blue concentrations from 0 to 0.4 μmol/mL, the sensor response is linear (R = 0.9496). A concentration variation of 0.1 μm...

Evanescent field response to immunoassay layer thickness on planar waveguides.

The response of a compact photonic immunoassay biosensor based on a planar waveguide to variation in antigen (C-reactive protein) concentration as well as waveguide ridge height has been investigated. Near-field scanning optical microscope measurements indicate 1.7%nm and 3.3%nm top surface optical intensity modulation due to changes in effective adlayer thickness on waveguides with 16.5 and 10...