Reducing coherent noise in interference systems using the phase modulation technique

Abstract

The phase modulation technique is adopted to reduce the coherent noise that arises from spurious interference. By choosing an appropriate driving signal, the method can reduce the coherent function of coherent noise to a great degree while keeping the coherent function of a coherent signal nearly unchanged. Simulation results show that for the grating interferometer, the phase error caused by coherent noise is reduced by 81.53% on average. For the Twyman interferometer, the fringe quality and contrast deteriorated by coherent noise are significantly improved. Furthermore, an experiment is set up in the phase-modulated Twyman interferometer to verify the feasibility of the principle. It is concluded that the method is effective to reduce the coherent noise in interference systems.

External Modulation Laser Module Assembly for Improving Measurement Performance of Homodyne Interferometry

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Cycle-consistent deep learning approach to coherent noise reduction in optical diffraction tomography

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