Separation of FBG wavelength mixed caused by temperature and vibration based on improved Fast-ICA and self-adapting

The purpose of conventional techniques for multiplexing fiber Bragg gratings (FBGs) is that each FBG has its own wavelength or unique intensity of reflected light. The cost pf per channel is at least of a few hundred dollars. All these limit the FBG points increasing at fiber measuring system. Based on improved Fast-ICA and self-adapting, this paper focuses on the separation of two same wavelength FBGs mixing model caused by temperature and vibration. Simulation experiment is carried out based on the initial wavelengths of two FBGs are both 1550.515nm and the temperature fluctuation range is 0-0.5°C and amplitude and frequency of exterior vibration are 0.01nm and 10Hz. Simulation data show that the separation steps consume 1.3884s and mean and mean square of absolute errors between the original and separated signals are 8.11·10-9, -5.83·10-12, and 2.57·10-6, 2.42·10-9, correspondingly. Therefore, through using this separation method, two same wavelength FBGs could achieve simultaneously measurement of temperature and vibration at one channel. This could double measuring points of fiber detection system, effectively.