title: Simultaneous measurement of refractive index and temperature based on intensity demodulation using matching grating method.
abstract: A solution refractive index (SRI) and temperature simultaneous measurement sensor with intensity-demodulation system based on matching grating method were demonstrated. Long period grating written in a photonic crystal fiber (LPG-PCF), provides temperature stable and wavelength dependent optical intensity transmission. The reflective peaks of two fiber Bragg gratings (FBGs), one of which is etched then sensitive to both SRI and temperature, another (FBG2) is only sensitive to temperature, were located in the same linear range of the LPG-PCF's transmission spectrum. An identical FBG with FBG2 was chosen as a matching FBG. When environments (SRI and temperature) change, the wavelength shifts of the FBGs are translated effectively to the reflection intensity changes. By monitoring output lights of unmatching and matching paths, the SRI and temperature were deduced by a signal processing unit. Experimental results show that the simultaneous refractive index and temperature measurement system work well. The proposed sensor system is compact and suitable for in situ applications at lower cost.
authors.affiliation: Institute of Optoelectronic Technology, China Jiliang University, Hangzhou 310018, People's Republic of China.
authors.forename: Liang
authors.initials: L
authors.lastname: Qi
authors.forename: Chun-Liu
authors.initials: CL
authors.lastname: Zhao
authors.forename: Juan
authors.initials: J
authors.lastname: Kang
authors.forename: Yongxing
authors.initials: Y
authors.lastname: Jin
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Wang
authors.forename: Manping
authors.initials: M
authors.lastname: Ye
authors.forename: Shangzhong
authors.initials: S
authors.lastname: Jin
mesh_terms: D055096:Optical Devices; D055620:Optical Phenomena; D013696:Temperature; D013997:Time Factors; D014867:Water
chemical_list: D014867:Water