Development of a high resolution optical-fiber tilt sensor by F-P filter

A high-resolution tilt sensor is developed, which is composed of a pair of optical fiber collimators and a simple pendulum with an F-P filter. The tilt angle is measured by demodulating the shift of center wavelength of F-P filter, which is caused by incidence angle changing. The relationship between tilted angle and the center wavelength is deduced. Calibration experiment results also confirm the deduction, and show that it is easy to obtain a high resolution. Setting the initial angle to 6 degree, the measurement range is ±3 degree, its average sensitivity is 1104pm/degree, and its average resolution is as high as 0.0009 degree.