Guei-Ru LIN^1*, Hung-Ying CHANG¹, Ming-Yue FU², Hao-Jan SHENG³, and Wen-Fung LIU³

¹Ph.D. Program in Electrical and Communications Engineering, Feng Chia University, Taichung 40724, Taiwan, R.O.C.
²Department of Avionics Engineering, Air Force Academy, Kaohsiung 82047, Taiwan, R.O.C.
³Department of Electrical Engineering, Feng Chia University, Taichung 40724, Taiwan, R.O.C.

(Received March 17, 2014; Revised May 30, 2014; Accepted June 2, 2014)

We proposed a novel refractive index sensor based on a side-polishing fiber to be cascaded with a stress-induced long period fiber grating (LPG), which is created by applying a force to a V-grooved plate on the single mode fiber with micro-bending deformation. When the refractive index (RI) surrounding the side-polishing surface is changed, the LPG-induced cladding mode light could be coupled back to the core mode, so that it will result in the magnitude variation of LPG loss-peak. This property of index sensing based on the stress-induced LPG by monitoring the power-level change may be exploited in chemical sensing and environmental monitoring applications.

Key words: fiber sensor, long period grating, stress, refractive index sensor

^*E-mail address: gweiru@gmail.com