Optical Fiber Sensors: Optical Sources

Fiber optic interferometric hydrophone using fiber Bragg grating with time division multiplexing

“…2(a) are similar to the à e-mail: okawara@jda-trdi.go.jp prototype hydrophone [6]. Practical fibers are produced with losses below 0.2 dB/km near 1,550 nm [10]; therefore, we assume A ¼ 0:02 dB. The measured insertion loss of hydrophone Y is 0.9 dB; therefore, we consider this value as a representative loss of the fiber coil (B ¼ 0:9 dB).…”

Strain Measurement Using Embedded Fiber Bragg Grating Sensors Inside an Anchored Carbon Fiber Polymer Reinforcement Prestressing Rod for Structural Monitoring

“…Initially, the required length of fiber into which the different FBG sensors were to be written was stripped and, using phase mask technique [5], all the sensors were written manually by shifting the fiber by 10 mm on each occasion, while at the same time changing the corresponding phase mask to allow a series of different sensors at wavelengths separated by 5 nm to be written. Fig.…”

“…To do so a series of FBG sensors is fabricated along a very short length of fiber to allow measurements to be taken over a minimal length of CFRP bar. FBGs are now an increasingly accepted technology offering a number of advantages for many engineering applications such as structural health monitoring, damage assessment and in monitoring engineering materials [5], [6]. Such sensors have been successfully used in several engineering fields to measure strain, temperature, pressure and monitoring applications for industrial and civil structures [7]- [10].…”

Fast-Response High-Temperature Microfiber Coupler Tip Thermometer

“…he use of optical fibers for temperature monitoring has been widely investigated [1,2] because of their immunity to electromagnetic interference and possibility to work in contact with explosives. Fiber Bragg gratings (FBGs) [3][4][5][6] are possibly the most commonly investigated optical fiber devices for temperature monitoring, as they can reach temperatures as high as 800 ºC [7] when inscribed in telecom optical fibers.…”