| Title |
Optical Fiber Sensor Capable of Separately Measuring Twist and TemperatureUsing Phase-Shifted Transmission Grating Written on Double-Clad Fiber |
| Authors |
Jinsil Han ; Yong Wook Lee |
| DOI |
http://doi.org/10.5207/JIEIE.2021.35.2.042 |
| Keywords |
Double-clad fiber; Fiber transmission grating; Optical fiber sensor; Phase shift; Simultaneousmeasurement; Temperature; Torsion; Twist |
| Abstract |
In this paper, we propose an optical fiber sensor capable of separately measuring twist and temperature by incorporating a phase-shifted transmission grating written on double-clad fiber(DCF) with a CO2 laser. The sensor head exhibited two separate attenuation dips in the resonance wavelength band, and these dips were selected as indicator dips denoted by LD and RD. The torsion and temperature responses of both dips were investigated in a twist angle range from -300° to 300° and a temperature range from 30 to 100°C. When a twist angle increased from 0° to 300°, LD and RD showed red shifts. In contrast, when a twist angle decreased from 0° to -300°, they showed blue shifts. In terms of the temperature response, LD and RD showed red shifts as the ambient temperature increased. As a result, it is confirmed that the torsion and temperature sensitivities of LD and RD are different and the two dips show linear behavior when the two variables (i.e., twist and temperature) are applied to the sensor head, so that changes in torsion and temperature can be separately estimated using the sensitivity coefficient matrix. |