A system for accurate balancing and controlled unbalancing of the optical path difference in all-fiber optical interferometers is described. Interferometers with various arm lengths (1-30 m) and with initial optical path differences of as much as 1 cm have been Read More …
Category: Research activities
A simple fiber-optic vehicle axle detector for roadways
This paper presents a fiber-optic vehicle axle detector for roadways. It is based on a fiber-optic Michelson interferometer that is mounted directly into the road surface. The fully dielectric design allows for remote operation of the sensor via a long Read More …
A Plastic Optical Fiber Microbend sensor Used as a Low-Cost Anti-Squeeze Detector
This paper presents a low-cost fiber optic anti-squeeze sensor, suitable for use in high-volume cost driven applications. The sensor, used as a car window anti-squeeze detector, complies with EC 2000/4/EC and U.S. Federal Motor Vehicle Safety Standard No. 118. The Read More …
Monitoring the Evaporation of Fluids from Fiber-Optic Micro-Cell Cavities
Fiber-optic sensors provide remote access, are readily embedded within structures, and can operate in harsh environments. Nevertheless, fiber-optic sensing of liquids has been largely restricted to measurements of refractive index and absorption spectroscopy. The temporal dynamics of fluid evaporation have Read More …
Cost-efficient speckle interferometry with plastic optical fiber for unobtrusive monitoring of human vital signs
A cost-efficient plastic optical fiber (POF) system for unobtrusive monitoring of human vital signs is presented. The system is based on speckle interferometry. A laser diode is butt-coupled to the POF whose exit face projects speckle patterns onto a linear Read More …
Focused ion beam post-processing of optical fiber Fabry-Perot cavities for sensing applications
Focused ion beam technology is combined with chemical etching of specifically designed fibers to create Fabry-Perot interferometers. Hydrofluoric acid is used to etch special fibers and create microwires with diameters of 15 ?m. These microwires are then milled with a Read More …
Monitoring and analysis of pendant droplets evaporation using bare and monolayer-coated optical fiber facets
The monitoring of sub nano-liter pendant liquid droplets, during their evaporation from the cleaved facet of a standard optical fiber, is proposed and demonstrated. The combined reflections of incident light from the two boundaries, between fiber and liquid and between Read More …
Quasi-distributed twist/torsion sensor
This paper presents a fiber-optic quasi-distributed in-line twist/rotation sensor. The presented sensor consists of a polarization maintaining lead-in fiber and series of in-line fiber polarizers with integrated semi-reflective mirrors that are interconnected by a standard single mode fiber. Sections of Read More …
Miniature, all-fiber rotation sensor based on temperature compensated wave plate
This paper presents a miniature, all-fiber fiber optic twist/rotation sensor. The proposed sensor consists of polarization maintaining lead-in fiber (PMF), a short section of standard (fully circularly symmetric) single-mode fiber, which is exposed to twist/axial rotation, an all-fiber quarter-wave wave Read More …
In-line, fiber-optic polarimetric twist/torsion sensor
This letter presents an optical fiber twist/torsion sensor that utilizes dissimilar polarization-preserving characteristics of standard single-mode and high-birefringence fibers. When only one polarization mode of the highbirefringence fiber is excited, spatial orientation of the E-field vector follows the fiber’s principal Read More …