Multi Long-Period Gratings in a Fiber Carved and Written by a CO_2 Laserfor Distributed Sensing

摘要

A multi long-period grating (multi-LPG) sensor has been proposed for distributed sensing by multiplexing different resonant wavelength peaks in one fiber. To fabricate the multi-LPG sensor, a carved LPG has also been proposed for easy fabrication of the multi-LPGs with different resonant wavelengths in a similar loss spectrum. The 2-LPG sensor was fabricated in a fiber successfully, containing carved and uncarved LPGs. The resonant wavelength shifts were 23 - 64 nrn, depending on the carved depth. The temperature dependence of the resonant wavelength was an order of 0.06 nm/deg. As a result, the resonant wavelength peaks were multiplexed and demultiplexed successfully at a temperature range of 10-80 C.