scholarly journals Smartphone-based hybrid 3D profilometry with extended imaging depth range based on binary code and phase-shifting

OSA Continuum ◽  
2021 ◽  
Author(s):  
Szu-Yu Chen ◽  
Han-Hsien Wang
Keyword(s):  
Binary Code ◽  
Phase Shifting ◽  
Depth Range ◽  
3D Profilometry ◽  
Imaging Depth

Phase-shifting algorithm to achieve high-speed long-depth-range probing by frequency-domain optical coherence tomography

2003 ◽  
Vol 28 (22) ◽  
pp. 2201 ◽  
Author(s):  
Rainer A. Leitgeb ◽  
Christoph K. Hitzenberger ◽  
Adolf F. Fercher ◽  
Tomasz Bajraszewski
Keyword(s):  
Optical Coherence Tomography ◽  
Frequency Domain ◽  
High Speed ◽  
Phase Shifting ◽  
Depth Range ◽  
Optical Coherence

scholarly journals Telecentric 3D profilometry based on phase-shifting fringe projection

2014 ◽  
Vol 22 (26) ◽  
pp. 31826 ◽  
Author(s):  
Dong Li ◽  
Chunyang Liu ◽  
Jindong Tian
Keyword(s):  
Phase Shifting ◽  
Fringe Projection ◽  
3D Profilometry

A simple system of swept source optical coherence tomography for a large imaging depth range

2019 ◽  
Vol 431 ◽  
pp. 51-57
Author(s):  
Xuan Wang ◽  
Zhongliang Li ◽  
Nan Nan ◽  
Yang Bu ◽  
Aijun Zeng ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Simple System ◽  
Depth Range ◽  
Optical Coherence ◽  
Swept Source ◽  
Imaging Depth

scholarly journals A photoacoustic imaging system with variable gain at different depths

2018 ◽  
Vol 11 (05) ◽  
pp. 1850022 ◽  
Author(s):  
Tian Guan ◽  
Yao Li ◽  
Muqun Yang ◽  
Yong Jiang ◽  
Yonghong He
Keyword(s):  
Nude Mice ◽  
Photoacoustic Imaging ◽  
The Body ◽  
Chicken Breast ◽  
Processing Unit ◽  
Depth Range ◽  
Variable Gain ◽  
Imaging Results ◽  
Different Depths ◽  
Imaging Depth

We established a photoacoustic imaging (PAI) system that can provide variable gain at different depths. The PAI system consists of a pulsed laser with an optical parametric oscillator working at a 728[Formula: see text]nm wavelength and an imaging-acquisition-and-processing unit with an ultrasound transducer. A voltage-controlled attenuator was used to realize variable gain at different depths when acquiring PAI signals. The proof-of-concept imaging results for variable gain at different depths were achieved using specific phantoms. Both resolution and optical contrast obtained through the results of variable gain for a targeted depth range are better than those of constant gain for all depths. To further testify the function, we imaged the sagittal section of the body of in vivo nude mice. In addition, we imaged an absorption sample embedded in a chicken breast tissue, reaching a maximum imaging depth of [Formula: see text]4.6[Formula: see text]cm. The results obtained using the proposed method showed better resolution and contrast than when using 50[Formula: see text]dB gain for all depths. The depth range resolution was [Formula: see text]1[Formula: see text]mm, and the maximum imaging depth of our system reached [Formula: see text]4.6[Formula: see text]cm. Furthermore, blood vessels can be revealed and targeted depth range can be selected in nude mice imaging.

scholarly journals Smart optical coherence tomography for ultra-deep imaging through highly scattering media

2016 ◽  
Vol 2 (11) ◽  
pp. e1600370 ◽  
Author(s):  
Amaury Badon ◽  
Dayan Li ◽  
Geoffroy Lerosey ◽  
A. Claude Boccara ◽  
Mathias Fink ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Multiple Scattering ◽  
Soft Tissues ◽  
Coherence Time ◽  
Tissue Imaging ◽  
Depth Range ◽  
Optical Coherence ◽  
Scattering Media ◽  
Depth Limit ◽  
Imaging Depth

Multiple scattering of waves in disordered media is a nightmare whether it is for detection or imaging purposes. So far, the best approach to get rid of multiple scattering is optical coherence tomography. This basically combines confocal microscopy and coherence time gating to discriminate ballistic photons from a predominant multiple scattering background. Nevertheless, the imaging-depth range remains limited to 1 mm at best in human soft tissues because of aberrations and multiple scattering. We propose a matrix approach of optical imaging to push back this fundamental limit. By combining a matrix discrimination of ballistic waves and iterative time reversal, we show, both theoretically and experimentally, an extension of the imaging-depth limit by at least a factor of 2 compared to optical coherence tomography. In particular, the reported experiment demonstrates imaging through a strongly scattering layer from which only 1 reflected photon out of 1000 billion is ballistic. This approach opens a new route toward ultra-deep tissue imaging.

scholarly journals Investigation of Phase Pattern Modulation for Digital Fringe Projection Profilometry

2020 ◽  
Vol 20 (1) ◽  
pp. 43-49
Author(s):  
Cheng-Yang Liu ◽  
Chung-Yi Wang
Keyword(s):  
Three Dimensional ◽  
Phase Shifting ◽  
Fringe Projection ◽  
Depth Range ◽  
Digital Fringe Projection ◽  
Great Possibility ◽  
Fringe Patterns ◽  
Pattern Modulation ◽  
Profile Reconstruction ◽  
Fringe Projection Profilometry

AbstractThe fringe projection profilometry with sinusoidal patterns based on phase-shifting algorithms is commonly distorted by the nonlinear intensity response of commercial projector. In order to solve this issue, sinusoidal width modulation is presented to generate binary sinusoidal patterns for defocusing the projection. However, the residual errors in the phase maps are usually notable for highly accurate three-dimensional shape measurements. In this paper, we propose the fringe patterns of the sinusoidal, square, and triangular periodic waveforms with seven-step phase-shifting algorithm to further improve the accuracy of three-dimensional profile reconstruction. The absolute phase values are calculated by using quality guided path unwrapping. We learn that by properly selecting fringe patterns according to the target shape, the undesired harmonics of the measured surface have negligible effect on the phase values. The experiments are presented to verify the imaging performances of three fringe patterns for different testing targets. The triangular fringe patterns are suitable for the shape measurements of complex targets with curved surfaces. The results provide a great possibility for high-accuracy shape measurement technique with wider measuring depth range.

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