Fiber-optic sensors have many advantages, including small size, light weight, immunity to electromagnetic interference, and the capability of remote sensing. Fiber-tip sensors are fabricated on a fiber tip and are the smallest type of fiber-optic sensor. The fiber-tip sensors have attracted a great deal of attention in past years for pressure, temperature, and acoustic sensing. In this thesis, ...

In this study, we fabricated a sapphire based fiber-optic radiation sensor. To evaluate the fiberoptic radiation sensor, we measured the spectrum and intensity of the luminescence generated from the fiber-optic radiation sensor according to the thickness of the PMMA block by irradiation of gamma rays emitted from a Co-60 source. And the result was compared with the value calculated from the for...

To detect external vibration signals on the latticed fence structure, distributed fiber optic sensor using Sagnac interferometer was fabricated and tested. Because of easy construction Sagnac interferometer was selected rather than MachZehnder type. The latticed structure fabricated with dimension of 180cm in width and 180cm in height, the optical fiber, 50m in length, distributed and fixed on ...

Liquid sealing is an effective method to convert a fiber-optic refractometer into a simple and highly sensitive temperature sensor. A refractometer based on the thin-core fiber modal interferometer is sealed in a capillary tube filled with Cargille oil. Due to the thermo-optic effect of the sealing liquid, the high refractive-index sensitivity refractometer is subsequently sensitive to the ambi...

Fiber optical current sensors based on Faraday effect have a lot of advantages over conventional current sensors and have been studied extensively. To eliminate the vibration sensitivity, a light path of reflective fiber optic current sensor improved is proposed, which makes discharge of Sagnac effect with Sagnac effect itself and do not disturb Faraday Effect at all. The reliability of the sys...

The surface mounted piezoceramic transducers and fiber optic sensor can detect signals in both symmetric and antisymmetric Lamb wave modes. Hanning windowed sine torn bursts were used for the piezoceramic transducer excitation signals. In order to overcome the difficulties in the signal processing of the simultaneous modes, the symmetric and antisymmetric modes were separated by using the two s...

In this study, a wavelength shifting fiber that shifts ultra-violet and blue light to green light was employed as a sensor probe of a fiber-optic Cerenkov radiation sensor. In order to characterize Cerenkov radiation generated in the developed wavelength shifting fiber and a plastic optical fiber, spectra and intensities of Cerenkov radiation were measured with a spectrometer. The spectral peak...

A fiber optic interferometric sensor with an intrinsic transducer along a length of the fiber is presented for ultrasound measurements of the acoustic emission from partial discharges inside oil-filled power apparatus. The sensor is designed for high sensitivity measurements in a harsh electromagnetic field environment, with wide temperature changes and immersion in oil. It allows enough sensit...