Date of Publication :28th February 2018
Abstract: In Optical Interferometric Sensors, it is important to precisely monitor changes in fringes which give change in phase information of a signal. The detection of a change in phase provides information on measurable physical parameters like the change in displacement, temperature, strain, etc. These parameters may change with respect to time, therefore; it is needed to monitor continuously changes in phase. The stepping interferometer technique is one of the most widely used techniques for phase detection. During this technique, the phase is continuously modified with known step size and therefore the detector integrates the intensity at every point over a range of phases. The various algorithms have been reported like 3-point, 4-point and much more for measuring phase shift with their own advantages and disadvantages. The various system errors like quantization of the detector signal, miscalibration of the phase shifter, detector nonlinearities, aberrations in optics measuring device, vibrations and air turbulence can affect the phase measurement. In this paper, the effect of such noises on phase detection has been analyzed to provide the least error on the measurement of phase information with high-speed measurements. It has been observed that 4-point & 5-point methods have less effect on noises interface during phase detection with noise interface 1-5% in the detected signal.
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