Slightly off-axis flipping digital holography using a reflective grating

Bai, Hongyi; Min, Rui; Yang, Ziheng; Zhu, Fuzhen

doi:10.1088/2040-8986/ab6b85

Cited by 3 publications

(5 citation statements)

References 37 publications

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“…It attempts the space-bandwidth product optimization by means of full spectral separation of conjugated object lobes, while leaving the autocorrelation term partially overlapped with information carrying cross-correlation terms [38][39][40][41][42][43][44][45][46][47][48][49][50][51][52] . Slightly off-axis phase demodulation is presently facilitated mainly by imposing restrictions on object and reference beams [38][39][40] , utilizing subtraction of two images [41][42][43][44][45][46][47] , employing two wavelengths 48 , or basing on the 1D limited processing [49][50][51][52] , however. In this contribution we are focusing on accurate bi-dimensional single-shot approaches as ability to study full-field dynamic events is fundamental in biomedicine.…”

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confidence: 99%

Variational Hilbert Quantitative Phase Imaging

Trusiak

Cywińska

Micó

et al. 2020

Sci Rep

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Utilizing the refractive index as the endogenous contrast agent to noninvasively study transparent cells is a working principle of emerging quantitative phase imaging (QPI). In this contribution, we propose the Variational Hilbert Quantitative Phase Imaging (VHQPI)-end-to-end purely computational add-on module able to improve performance of a QPI-unit without hardware modifications. The VHQPI, deploying unique merger of tailored variational image decomposition and enhanced Hilbert spiral transform, adaptively provides high quality map of sample-induced phase delay, accepting particularly wide range of input single-shot interferograms (from off-axis to quasi on-axis configurations). It especially promotes high space-bandwidth-product QPI configurations alleviating the spectral overlapping problem. The VHQPI is tailored to deal with cumbersome interference patterns related to detailed locally varying biological objects with possibly high dynamic range of phase and relatively low carrier. In post-processing, the slowly varying phase-term associated with the instrumental optical aberrations is eliminated upon variational analysis to further boost the phase-imaging capabilities. The VHQPI is thoroughly studied employing numerical simulations and successfully validated using static and dynamic cells phase-analysis. It compares favorably with other single-shot phase reconstruction techniques based on the Fourier and Hilbert-Huang transforms, both in terms of visual inspection and quantitative evaluation, potentially opening up new possibilities in QPI. Optical imaging is a central aspect of biological research, biomedical examination, and medical diagnosis. Optical microscope is indispensable in biological and medical research facilitating a "seeing is believing" paradigm 1. Despite its rich history and well-established position, significant efforts are contemporarily put on developing new imaging modalities enabling enhanced resolution, contrast, depth, speed and information content. Among a suite of modern microscopy techniques, quantitative phase imaging (QPI) 2-4 stands out as a vividly blossoming label-free approach. It provides unique means for imaging cells and tissues merging beneficial features identified with microscopy 1 , interferometry and holography 5 , and numerical computations. Using refractive index as the endogenous contrast agent 6,7 QPI numerically converts recorded interference pattern into a nanoscale-precise subcellular-specific map of optical delay introduced by examined transparent specimen 7-9. This non-phototoxic non-destructive imaging technique brings biology and metrology closer as it generates quantitative maps of analyzed live bio-structure (related to cell mass, volume, surface area, and their evolutions in time). Therefore, QPI enables upgrading phase-contrast based 6 visualization of the sample to stain-free non-invasive measurement of sample-induced optical phase delay (related to refractive index and/or thickness variations). Impressive details can be imaged, e.g., via super-resolut...

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mentioning

confidence: 99%

Variational Hilbert Quantitative Phase Imaging

Trusiak

Cywińska

Micó

et al. 2020

Sci Rep

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“…In order to further evaluate the effectiveness of the proposed method, we performed quantitative calculations of the unwrapped phase. The 1D optical path difference (OPD) profile [6] is mapped along the blue dashed line in Figure 7h, as indicated by the blue line in Figure 8. A polynomial fit to the measured profile was performed to obtain the red dashed fitting line in Figure 8.…”

Section: Phase Reconstruction Of Thick Phase Specimenmentioning

confidence: 99%

“…Slightly off-axis digital holography (SODH) has gained increased attention because it is faster than on-axis DH in reconstructing images and achieves better resolution of reconstructed images than off-axis DH. In SODH, due to the elimination of the direct current (DC) term, there are only two cross-correlation terms in the spectrum, which are separated from each other, and they play a key role in extracting effective information [6]. SODH can be achieved by integrating off-axis configurations and phase shift techniques.…”

Section: Introductionmentioning

confidence: 99%

“…However, the pinhole filter which is used must meet the strict system parameters. The first author proposed a SODH method based on flipping interference [6]. This device uses a modified flip module with a reflection grating and a retro-reflector consisting of two reflector structures.…”

Section: Introductionmentioning

confidence: 99%

“…One of the advantages of this proposed system is its simplicity and flexibility in terms of optical equipment and alignment. Compared with the previous work on SODH with a grating to introduce phase shift [6,15], the proposed method does not require special optical elements, such as a pinhole, reflective grating, or retro-reflector of two mirrors, or the strict limitations of the system parameters. In addition, our method makes installation and adjustment easier without requiring specialized skills.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Slightly Off-Axis Digital Holography Using a Transmission Grating and GPU-Accelerated Parallel Phase Reconstruction

Bai,

Chen,

Sun

et al. 2023

Photonics

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Slightly off-axis digital holography is proposed using transmission grating to obtain quantitative phase distribution. The experimental device is based on an improved 4f optical system in which a two-window input plane is used to form the object beam and reference beam. Then, the two beams are diffracted into multiple orders by the transmission grating placed at the Fourier plane. By applying a modified Michelson configuration, the interference patterns can be generated by the object and reference beams from different diffraction orders. After translating the grating, a random phase shift can be introduced to the hologram. To demonstrate the feasibility of our method, both thick and thin phase specimens are retrieved using two carrier phase-shifting holograms. Furthermore, we use the phase reconstruction algorithm based on the NVIDIA CUDA programming model to reduce the retrieval time. Meanwhile, we optimize the discrete cosine transform (DCT)-based least-squares unwrapping algorithm to unwrap the phase. By porting the entire phase reconstruction process to the graphics processing unit (GPU), the phase retrieval acceleration and execution efficiency significantly improve. To demonstrate the feasibility of our method, it is found that our method can measure the surface profiles of standard elements, such as a plano-convex cylinder lens and a microlens array, with a relative error of about 0.5%. For holograms with a different phase shift, the root-mean-square (RMS) value of the phase difference for the main imaging region is about 0.2 rad. By accelerating the phase reconstruction with GPU implementation, a speedup ratio of about 20× for the thick phase specimen and a speedup ratio of about 15× for the thin-phase specimen can be obtained for holograms with a pixel size of 1024 × 1024.

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Real-Time Phase Retrieval Based on Cube-Corner Prisms Single Exposure

Chen

Zhu

et al. 2022

Photonics

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The phase retrieval method based on the Transport of Intensity Equation needs to record the light intensity information on two or more planes perpendicular to the optical axis propagating along the optical axis. Usually, a single CCD camera is moved back and forth for recording, which not only brings the corresponding mechanical errors, but also has a certain time difference between the collected intensity images, which cannot meet the real-time requirements. In this paper, a single phase retrieval technique based on cube-corner prisms is proposed. This method can simultaneously collect the required initial intensity image in a single exposure, and then calculate the phase after registration and repair, so as to obtain high-precision results. According to the parallel reflection characteristics of the cube-corner prisms, the experimental system designed correspondingly can not only stagger the two beams separated by the beam splitter, but also ensure that the upper and lower propagation distances of a single beam are equal. Finally, the accuracy and effectiveness of the proposed method are fully verified by simulation experiments and experimental measurements.

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Slightly off-axis flipping digital holography using a reflective grating

Cited by 3 publications

References 37 publications

Variational Hilbert Quantitative Phase Imaging

Variational Hilbert Quantitative Phase Imaging

Slightly Off-Axis Digital Holography Using a Transmission Grating and GPU-Accelerated Parallel Phase Reconstruction

Real-Time Phase Retrieval Based on Cube-Corner Prisms Single Exposure

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