A high-sensitivity fiber accelerometer based on multilayer fiber coils is proposed. Acceleration sensing principle of the sensor is analyzed in theory, and with the finite element software, simulation model is built. Two kinds of fiber optic accelerometers with different multilayer fiber coils are designed, and the performance tests are conducted as well. Experimental results show that the sensitivity of accelerometer based on multilayer fiber coils can reach thousands rad/g, and the equivalent transfer coefficient between different layers in multilayer fiber coils is 0.39.
A detecting method based on Fizeau interferometer for fiber-optic displacement sensing is presented to detect highprecision
displacement in nanometer scale. On the basis of optical interferometry and common-path Fizeau
interferometer, micro displacement can be detected by accurately measuring the distance changes between the surfaces
of fiber-optic collimator and measuring mirror. Its characteristics are as follows: with common-path interferometer,
dependence of energy transmitting fiber to ambient temperature is eliminated, then the effect of ambient temperature
variation to the system is reduced; with the method of phase generated carrier modulation/demodulation instead of
electric-control phase modulator, the optical path is formed with all-fiber components to improve the application
flexibility in the system; by micro fiber-optic collimator with diameter of 1mm, the overall dimension of the
displacement sensor is greatly reduced, which makes the use of the sensor more flexible. In the paper, the structure and
parameters of miniature all-fiber common-path fiber-optic displacement sensor is studied, the experimental platform for
high-precision displacement calibration is established, and a series of performance tests are completed. Experimental
results show: with the working distance of 0-14mm, the measuring resolution of the miniature fiber-optic displacement
sensor can reach 20nm, and the measuring dynamic range can get 116.9dB, which indicate that the miniature fiber-optic
displacement sensor has superior performances with high resolution, high precision and large dynamic range.