Wavelength Division Multiplexing/Spectral Amplitude Coding Applications in Fiber Vibration Sensor Systems

This paper presents a wavelength division multiplexing/spectral amplitude coding system with optical code-division multiple-access, for applications using fiber vibration sensors. The device makes use of fiber Bragg grating (FBG) etching on optical fibers to provide encoding/decoding functionality. According to the orthogonal properties of spectral amplitude coding (SAC) using m-sequence code, the encoding- decoding devices that employ FBG filters provide a considerable reduction in multiple access interference in optical code division multiple access systems. The proposed fiber vibration sensor located between the encoder and optical circulator enables the measurement of multiple points. Experimental results reveal that the proposed sensor detects a variety of vibrational signals.