Two-step diffraction phase imaging method and corresponding phase retrieval method

Abstract

The invention discloses a two-step diffraction phase imaging method and a corresponding phase retrieval method. 0 scale diffracted by raster is adopted to form two-step geometric optical path interference patterns with high stability with +1 scale and -1 scale diffraction light in sequence; then the difference between the two interference patterns are calculated to eliminate background light intensity so as to apply Hilbert transform to retrieve phase information of samples. Compared with frequently-used phase retrieval methods of off-axis interference, high-pass filtering is not needed in the methods, high-frequency information is reserved integrally, the phase retrieval speed is high and the two-step diffraction imaging method is applicable to all off-axis interferences including slight off-axis interference. The two-step diffraction phase imaging method and the corresponding phase retrieval method have a wide utility value and an application prospect in phase microscopy, especially in the application field of transparent samples such as biological cell phase imaging and phase measuring.

Description

technical field [0001] The invention belongs to the technical field of interference microscopic imaging, and in particular relates to a two-step diffraction phase microscopic imaging method based on grating diffraction and a corresponding phase recovery operation method. Background technique [0002] Optical microscopy technology has opened a door for the observation of microscopic things, and has played an important role in the fields of biology and medicine. Numerous biological samples, such as living cells, are mostly transparent and appear as phase objects. These samples can be imaged clearly and without damage using phase imaging techniques that convert between phase and intensity. At present, interferometric phase microscopy is the mainstream technology, which has the advantages of fast measurement speed and high resolution. [0003] In 2004, Professor Gabriel Popescu of the United States proposed Fourier phase microscopy technology, using the scattered light and non...

AI Technical Summary

Problems solved by technology

However, the phase shift needs to be determined by fitting the background fringe afterwards, which increases the complexity of phase recovery to a certain extent.

In addition, this technology uses the interference microscope with two optical paths, which does not have the advantage of a common optical path

[0004] To sum up, in the prior art, the phase information can be demodulated from a single off-axis interferogram, but off-axis interferometry cannot make full use of the spatial bandwidth of the CCD, and the commonly used background image high-pass filter will also cause the loss of high-frequency information; although there are some The technology uses two interferograms, such as the two-step slight off-axis interference proposed by AdamWax mentioned in the article, but it uses a dual-optical path interferometric imaging system, which is unstable and requires devices to achieve phase shift and needs to be measured separately

Images