Optical system for monitoring groundwater pressure and temperature using fiber Bragg gratings

Pressure Effects on the Temperature Sensitivity of Fiber Bragg Gratings

A 3-dimensional physical model was developed to relate the wavelength shifts resulting from temperature changes of fiber Bragg gratings (FBGs) to the thermal expansion coefficients, Young’s moduli of optical fibers, and thicknesses of coating polymers. Using this model the Bragg wavelength shifts were calculated and compared with the measured wavelength shifts of FBGs with various coating thick...

Plantar Pressure Detection with Fiber Bragg Gratings Sensing System

In this paper, a novel fiber-optic sensing system based on fiber Bragg gratings (FBGs) to measure foot plantar pressure is proposed. This study first explores the Pedar-X insole foot pressure types of the adult-size chart and then defines six measurement areas to effectively identify four foot types: neutral foot, cavus foot, supinated foot and flat foot. The plantar pressure signals are detect...

Bulk regeneration of optical fiber Bragg gratings.

The reliability and reproducibility of regenerated gratings for mass production is assessed through simultaneous bulk regeneration of 10 gratings. The gratings are characterized and variations are compared after each stage of fabrication, including seed (room-temperature UV fabrication), regeneration (annealing at 850°C), and postannealing (annealing at 1100°C). In terms of Bragg wavelength (λ(...

Fiber Bragg gratings in optical microfibers

Bandwidth compression optical processor using chirped fiber Bragg gratings

Chirped fiber Bragg gratings are used as low-loss, dispersion compensation modules for telecommunications applications. Here we use them to make an optical processor that compresses the bandwidth of electronic signals before digitization by an analog-to-digital converter. ©2007 Optical Society of America OCIS codes: (230.0250) Optoelectronics, (060.2360) Fiber optics and optical communications ...