In this letter, we report bending and strain sensitivities of helicoidal long-period fiber gratings fabricated by twisting single-mode fibers during CO2 laser irradiation. Linear spectral shifts of the resonant wavelengths under the bending and tensile strain were observed with the sensitivities of 11.7 nm/m-1 and 1.1 pm/μ ε, respectively. The corresponding transmission power variations at the resonance wavelength were 4.1/m-1 and 2.2 × 10-4dB/με, respectively. Detailed measurement techniques and sensor applications are discussed.
Bibliographical noteFunding Information:
Manuscript received April 20, 2009; revised May 24, 2009. First published June 10, 2009; current version published August 19, 2009. This work was supported in part by Korea Science and Engineering Foundation under Program ROA-2008-000-20054-0 and Program R15-2004-024-00000-0, by Korea Foundation for International Cooperation of Science under Program 2008-8-1893 (GOSPEL project), by the Institute of Industrial Technology Evaluation and Planning under Program 2007-8-2074 and Program 2008-8-1195, and by the Brain Korea 21 Project of the Korea Research Foundation.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering