Analysis of a novel sensor interrogation technique based on fiber cavity ring-down (CRD) loop and OTDR

Fiber Measurement Technique Based on OTDR

Optical properties of absorbing and non-absorbing aerosols retrieved by cavity ring down (CRD) spectroscopy

Application of cavity ring down (CRD) spectrometry for measuring the optical properties of pure and mixed laboratory-generated aerosols is presented. The extinction coefficient (α ext), extinction cross section (σ ext) and extinction efficiency (Q ext) were measured for polystyrene spheres (PSS), ammonium sulphate ((NH 4) 2 (SO 4)), sodium 5 chloride (NaCl), glutaric acid (GA), and Rhodamine-59...

An Optical Fiber Displacement Sensor Using RF Interrogation Technique

We propose a novel non-contact optical fiber displacement sensor. It uses a radio frequency (RF) interrogation technique which is based on bidirectional modulation of a Mach-Zehnder electro-optical modulator (MZ-EOM). The displacement is measured from the free spectral range (FSR) which is determined by the dip frequencies of the modulated MZ-EOM transfer function. In experiments, the proposed ...

Chemical Sensing Using Fiber Cavity Ring-Down Spectroscopy

Waveguide-based cavity ring-down spectroscopy (CRD) can be used for quantitative measurements of chemical concentrations in small amounts of liquid, in gases or in films. The change in ring-down time can be correlated to analyte concentration when using fiber optic sensing elements that change their attenuation in dependence of either sample absorption or refractive index. Two types of fiber ca...

Cavity ring-down spectroscopy sensor for detection of hydrogen chloride

A laser-based cavity ring-down spectroscopy (CRDS) sensor for measurement of hydrogen chloride (HCl) has been developed and characterized. The instrument uses light from a distributed-feedback diode laser at 1742 nm coupled to a high finesse optical cavity to make sensitive and quantifiable concentration measurements of HCl based on optical absorption. The instrument has a (1σ ) limit of detect...