Long-Period Grating Inscribed on Concatenated Double-Clad and Single-Clad Fiber for Simultaneous Measurement of Temperature and Refractive Index


In this letter, a kind of long-period fiber grating (LPFG) that is capable of simultaneous measurement of temperature and surrounding refractive index (RI) is fabricated and demonstrated. The compact LPFG is written on a piece of spliced standard single-mode fiber (SMF) and double-clad fiber (DCF) with the CO2 laser point-by-point irradiation technique. The LPFG section in the DCF is solely sensitive to temperature, while the section of the LPFG in the SMF is sensitive to both temperature and surrounding RI. After temperature and RI calibration, the LPFG has been used to measure the RI change of ethylene glycol with the change of temperature to demonstrate its capability for dual parameter simultaneous measurement.


Electrical and Computer Engineering


National Natural Science Foundation (China)
United States. Department of Energy


This work was supported in part by the National Natural Science Foundation of China under Grant 61107035 and in part by the U.S. Department of Energy under Grant DE-FE0001127.

Keywords and Phrases

Double-clad; Double-clad fiber; Fiber gratings; Fiber Sensor; Long period fiber grating; Long Period Gratings; Simultaneous measurement; Standard single mode fibers; Surrounding refractive indices (SRI); Carbon dioxide; Chemical sensors; Ethylene glycol; Refractive index; Single mode fibers; Fibers

International Standard Serial Number (ISSN)

1041-1135; 1941-0174

Document Type

Article - Journal

Document Version


File Type





© 2012 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Jul 2012