Femtosecond Laser Fabrication of Long Period Fiber Gratings and Applications in Refractive Index Sensing

Abstract

An improved point-by-point inscription method is proposed to fabricate long period fiber gratings (LPFGs) by using a laser operating at 800 nm with 35 fs duration pulses. The sensitivity to misalignment between the core and the focus is reduced by scanning a rectangular part on the fiber. LPFGs with an attenuation depth of 20 dB are achieved within the wavelength range of 1465-1575 nm. Characterization of the temperature sensitivity and thermal stability of the LPFGs is presented. A 5.6 nm wavelength shift and a 1.2 dB decrease in the attenuation peak are observed following heat treatment at 600 °C for 4 h. The fabricated LPFGs are used as refractive index sensors. The effect of heat treatment on the response of the LPFGs to refractive index changes is also studied.

Department(s)

Mechanical and Aerospace Engineering

Second Department

Electrical and Computer Engineering

Sponsor(s)

Ministry of Science and Technology of the People's Republic of China. 863 Program
National Natural Science Foundation (China)

Keywords and Phrases

Long Period Fiber Gratings; Refractive Index Sensor; Femtosecond lasers

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2011 Elsevier, All rights reserved.

Publication Date

01 Nov 2011

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