Title :
Sandwiched long-period gratings for simultaneous measurement of refractive index and temperature
Author :
Zhang, A. Ping ; Shao, Li-Yang ; Ding, Jin-Fei ; He, Sailing
Author_Institution :
Dept. of Opt. Eng., Zhejiang Univ., China
Abstract :
A simultaneous measurement of external refractive-index (RI) and temperature is presented by using a sandwiched structure of long-period gratings (LPGs). An LPG pair with codirectional coupling between the guided mode and a low-order cladding mode acts as a temperature sensor with low RI sensitivity, whereas another in-between LPG which couples the guided mode with a higher order cladding mode performs as an RI sensing element. The experimental results show such an all-LPG structure is not only suitable for use as a compact temperature-compensated RI sensor, but also convenient for fabrication.
Keywords :
diffraction gratings; fibre optic sensors; refractive index measurement; temperature measurement; temperature sensors; codirectional mode coupling; long-period gratings; low-order cladding mode; refractive index measurement; temperature measurement; temperature sensor; Biomedical optical imaging; Bragg gratings; Fiber gratings; Optical fiber sensors; Optical interferometry; Optical refraction; Optical sensors; Refractive index; Temperature measurement; Temperature sensors; Long-period fiber gratings; optical fiber sensor; refractive-index (RI) measurement; temperature sensor;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2005.857621
