You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither SPIE nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the SPIE website.
10 June 2006A novel long-period fiber grating torsion sensor
In this paper, we propose and demonstrate a novel torsion sensor based on a long-period fiber grating (LPFG) induced symmetrically by three beams of focused high-frequency CO2 laser pulses (20~24 kHz). Experimental results show, when the LPFG is twisted clockwise, the resonant wavelength shifts toward shorter wavelengths, and the peak loss decreases. When the LPFG is twisted anticlockwise, the resonant wavelength shifts toward longer wavelengths, and the peak loss increases. The resonant wavelength and the peak loss are all similarly proportional to the twist angle applied. Based on this LPFG, a new kind of fiber-optic torsion sensors can be made, which can not only directly measure the torsion angle, but also determine the torsion direction simultaneously by means of measuring the shift of the resonant wavelength and/or the peak loss of the LPFG.