Single- and Two-Phase Flow Characterization Using Optical Fiber Bragg Gratings

Single- and Two-Phase Flow Characterization Using Optical Fiber Bragg Gratings

Single- and two-phase flow characterization using optical fiber Bragg gratings (FBGs) is presented. The sensor unit consists of the optical fiber Bragg grating positioned transversely to the flow and fixed in the pipe walls. The hydrodynamic pressure applied by the liquid or air/liquid flow to the optical fiber induces deformation that can be detected by the FBG. Given that the applied pressure...

Electrically tunable Bragg gratings in single-mode polymer optical fiber.

We present what is to our knowledge the first demonstration of a tunable fiber Bragg grating device in polymer optical fiber that utilizes a thin-film resistive heater deposited on the surface of the fiber. The polymer fiber was coated via photochemical deposition of a Pd/Cu metallic layer with a procedure induced by vacuum-ultraviolet radiation at room temperature. The resulting device, when w...

Synthesis and characterization of fiber Bragg gratings

This thesis is mainly a study of theoretical issues in the field of fiber Bragg gratings. The synthesis problem of gratings is investigated in detail. This applies to synthesis based on desired, complex spectra in reflection as well as in transmission. In addition, methods for characterization of fiber gratings are proposed. For the synthesis problem of gratings, a genetic algorithm and a layer...

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