Phase-shift digital holographic high-speed imaging method and system

Abstract

The invention is applicable to the technical field of hologram photography and provides a phase-shift digital holographic high-speed imaging method which comprises the following steps: step A, using a light source to irradiate a target object to produce an object light carrying object information; step B, interfering the object light respectively with a zero phase-shift reference light and a pi phase-shift reference light, forming two holograms each time; step C, recovering an original light field of the target object according to the two holograms. The method provided by the invention can obtain two reference lights of zero phase shift and pi phase shift by one time through producing pi phase shift in one reference light with respect to the other reference light, avoid repeated phase shift and environmental change such as vibration and regulation error caused by the repeated phase shift, recover the original object light field by a simple algorithm according to the two holograms, effectively removing zero-order and conjugate images, and provide a feasible method for real-time recording in a high-velocity motion process.

Description

technical field [0001] The invention belongs to the technical field of holography, and in particular relates to a phase-shift digital holographic high-speed imaging method and system. Background technique [0002] Holography has been used in many aspects since it was proposed, such as three-dimensional imaging, shape measurement, etc., but traditional optical holography requires chemical wet processing, the process is complicated, and it is difficult to digitize, while digital holography uses digital cameras instead of photosensitive records. The medium can directly obtain the data, and the analysis is convenient and simple, so it has aroused the interest of many scholars. However, due to the limitation of large pixel size and small number of pixels in current digital cameras, off-axis holograms with small angles can only be recorded, and high spatial frequency information cannot be recorded. Coaxial holography can make full use of the space-bandwidth product of the camera,...

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Problems solved by technology

However, most of this method uses piezoelectric ceramics, rotating wave plates, etc. to achieve phase shift results, and requires multiple recordings of holograms with different phase shifts, so it cannot be applied to high-speed recording processes

In order to use the phase shift method to record the high-speed process, Japanese scholar Yasuhiro Awatsuji et al. proposed the method of parallel phase shift, which can record the high-speed process, but it needs to make an accurate mask, the process is complicated, and it can only record objects with a relatively uniform surface. For objects with large fluctuations, the error of the reproduction result is large

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