Abstract: A demodulation system for 3D-matrix multi-channel fiber optic sensing includes a wavelength swept optical source that generates an incident light, an optical frequency domain reflector and a balanced detector connected with the wavelength swept optical source through a fiber circulator. The optical frequency domain reflector includes a first optical path and a second optical path with a frequency shifter arranged on one or both of the optical paths. The optical frequency domain reflector outputs incident light to an optical switch module. The optical switch module selectively transmits the incident light to a sensor network as well as transmits the reflection light from the sensor network to the optical frequency domain reflector.

Abstract: An optical fiber rotary squeezer polarization controller, comprising a base, a left bracket and a right bracket respectively mounted at both ends of the base, characterized in that a shaft is rotatably mounted between the left bracket and the right bracket, the shaft having a through channel cut therein lengthwise for placement of an optical fiber, the shaft further being mounted with a squeezing apparatus corresponding to the channel. The present invention has altered the means by which an optical fiber is fixed onto the prior-art polarization controllers and has eliminated the clamps at both ends of the optical fiber. The shaft carries the squeezing apparatus to rotate to any desired angles while the optical fiber remains stationary under the effect of its own tension. As the optical fiber extends outwardly from either end of the shaft, it is restrained by its own tension and, therefore, will not rotate along with the shaft.