Synthetic wavelength interferometry based on windowed Fourier filtering

Synthetic wavelength interferometry is capable of realizing three-dimensional imaging of the macroscopic morphology of an object under a single exposure based on a short-wavelength light source. However, the measurement accuracy and imaging field of view are seriously affected by coherent scattering noise and detector sampling limitations. Based on the above problems, a method based on windowed Fourier filtering and spectrum-multiplexed is proposed. The coherent noise is effectively suppressed by windowed Fourier filtering, and the depth reconstruction accuracy is significantly improved. Meanwhile, by increasing the off-axis interference angle, a 3-fold imaging field of view expansion is realized without increasing the complexity of the optical path. The experimental results show that this method realizes a large field of view and high signal-to-noise ratio for three-dimensional measurement of macroscopic shape of an object under a single exposure, which provides a new way for high-precision three-dimensional reconstruction.