Fiber optic electric field sensors using polymer-dispersed liquid crystal coatings and evanescent field interactions
| Autor: | Toemsak Srikhirin, Massood Tabib-Azar, Grigory Adamovsky, Boonsong Sutapun, Jerome B. Lando |
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| Rok vydání: | 2000 |
| Předmět: |
Materials science
Optical fiber business.industry Orders of magnitude (temperature) Metals and Alloys Physics::Optics RC time constant Condensed Matter Physics Surfaces Coatings and Films Electronic Optical and Magnetic Materials law.invention Core (optical fiber) Optics Liquid crystal Fiber optic sensor law Electric field Electrical and Electronic Engineering business Instrumentation Refractive index |
| Zdroj: | Sensors and Actuators A: Physical. 84:134-139 |
| ISSN: | 0924-4247 |
| DOI: | 10.1016/s0924-4247(99)00352-0 |
| Popis: | We report a simple evanescent field fiber optic electric field sensor constructed by coating the exposed fiber optic core with a polymer-dispersed liquid crystal (PDLC). It is well known that the effective refractive index of the liquid-crystal polymers has a large dependence on the direction and the magnitude of an applied electric field. This dependence was large enough in our devices to enable simple transmission measurements to detect the presence of an applied electric field across the fiber optic. The sensors showed good sensitivity and reproducibility with its response dominated by the RC time constant of the structure rather than the response of the PDLC. Its response time was approximately 3 min with 15–20 min relaxation time. Using an electric circuit model of the device, we also discuss how the sensor's response time can be improved by many orders of magnitude. |
| Databáze: | OpenAIRE |
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