9 results on '"CHEN Zhiyan"'
Search Results
2. Amplified phase measurement of thin-film thickness by swept-source spectral interferometry
- Author
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Wen Bao, Chen Zhiyan, Cong Pan, Zhihua Ding, Peng Li, Yi Shen, and Zhao Chen
- Subjects
Materials science ,genetic structures ,business.industry ,Phase (waves) ,Magnitude (mathematics) ,eye diseases ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Condensed Matter::Soft Condensed Matter ,Physics::Fluid Dynamics ,Condensed Matter::Materials Science ,Nonlinear system ,Interferometry ,Optics ,Spectral envelope ,sense organs ,Sensitivity (control systems) ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,Thin film ,business ,Phase method - Abstract
Thin-film thickness measurement based on spectral phase method is limited by the magnitude of the nonlinear spectral phase. To increase the sensitivity, a swept-source interferometer with recirculating sample loop is developed to obtain an amplified spectral phase from the thin-film under measurement. The spectral phase of the complex reflectivity of the thin-film can be accumulated in multiple passages of the probing light to the thin-film. After removing the linear spectral phase from the retrieved spectral phase, amplified nonlinear spectral phase corresponding to the thin-film is obtained. Using this amplified nonlinear spectral phase in a fitting model, the thin-film thickness can be determined with an enhanced precision.
- Published
- 2015
3. Ultrawide-field parallel spectral domain optical coherence tomography for nondestructive inspection of glass
- Author
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Zhihua Ding, Peng Li, Xiaoping Wang, Yi Shen, Zhao Chen, and Chen Zhiyan
- Subjects
CMOS sensor ,Relay lens ,Materials science ,medicine.diagnostic_test ,Spectrometer ,business.industry ,Ranging ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,law.invention ,Lens (optics) ,Optics ,Parallel processing (DSP implementation) ,Optical coherence tomography ,law ,medicine ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,business ,Sensitivity (electronics) - Abstract
Aiming at the requirements of real-time inspection in material industry, an ultrawide-field parallel SD-OCT system capable of visualizing cross-sectional image of internal structures by a single shot of a 2-D CMOS camera is developed. To achieve ultrawide-field parallel detection, one meniscus lens with negative dioptric is introduced as an additional relay lens and imaging optics including sample arm, relay lenses and spectrometer are optimized as a whole for desirable imaging quality. The developed system has an ultrawide-field of 35 mm and an axial range of 8 mm in air. The maximum on-axis sensitivity and the axial resolution are experimentally determined to be 65 dB and 17.7 μm, respectively. The on-axis lateral resolution is measured to be 44 μm in parallel direction and 22 μm in scanning direction. The system is applied to obtain 3-D volume images of a set of glass-samples covering an area of about 28 mm by 15 mm with thicknesses ranging between 2.1 mm and 4 mm, from which defects such as solid inclusion, micro-deformation and bubble are identified either on the surfaces or inside the samples.
- Published
- 2015
4. Quasi-needle-like focus synthesized by optical coherence tomography
- Author
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Peng Li, Zhihua Ding, Chen Zhiyan, Jianrong Qiu, Wen Bao, and Yi Shen
- Subjects
Point spread function ,Physics ,Depth of focus ,medicine.diagnostic_test ,business.industry ,Spectral density ,02 engineering and technology ,Lateral resolution ,021001 nanoscience & nanotechnology ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Computer Science::Robotics ,010309 optics ,Optical imaging ,Optics ,Optical coherence tomography ,0103 physical sciences ,medicine ,0210 nano-technology ,Focus (optics) ,business ,Optical path length - Abstract
It is known that lateral resolution and depth of focus (DOF) in an optical imaging system are coupled, and a compromise between them has to be made. In this Letter, we propose to resolve the trade-off between lateral resolution and the DOF by a synthetic effective point spread function in optical path length (OPL) domain. A quasi-needle-like focus is synthesized by optical coherence tomography. We demonstrate that the synthesized quasi-needle-like focus provides a four-fold extension of a conventional DOF, while maintaining a high lateral resolution of 2.5 μm over a depth range of approximately 240 μm. The focal range can be further extended with more optical path length coded beams for synthesis involved.
- Published
- 2017
5. Research Progress on Parallel Spectral Domain Optical Coherence Tomography Technology
- Author
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邱建榕 Qiu Jianrong, 陈志彦 Chen Zhiyan, 丁志华 Ding Zhihua, and 沈毅 Shen Yi
- Subjects
Physics ,Optics ,Optical coherence tomography ,medicine.diagnostic_test ,business.industry ,medicine ,Spectral domain ,Electrical and Electronic Engineering ,business ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials - Published
- 2018
6. Identification of surface defects on glass by parallel spectral domain optical coherence tomography
- Author
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Chen Zhiyan, Peng Li, Zhihua Ding, Wen Bao, Xiaoping Wang, and Yi Shen
- Subjects
Surface (mathematics) ,Materials science ,medicine.diagnostic_test ,Computer simulation ,business.industry ,Phase (waves) ,Spectral density ,Spectral domain ,Signal ,Atomic and Molecular Physics, and Optics ,Identification (information) ,Optics ,Optical coherence tomography ,medicine ,business - Abstract
Defects can dramatically degrade glass quality, and automatic inspection is a trend of quality control in modern industry. One challenge in inspection in an uncontrolled environment is the misjudgment of fake defects (such as dust particles) as surface defects. Fortunately, optical changes within the periphery of a surface defect are usually introduced while those of a fake defect are not. The existence of changes within the defect peripheries can be adopted as a criterion for defect identification. However, modifications within defect peripheries can be too small to be noticeable in intensity based optical image of the glass surface, and misjudgments of modifications may occur due to the incorrectness in defect demarcation. Thus, a sensitive and reliable method for surface defect identification is demanded. To this end, a nondestructive method based on optical coherence tomography (OCT) is proposed to precisely demarcate surface defects and sensitively measure surface deformations. Suspected surface defects are demarcated using the algorithm based on complex difference from expectation. Modifications within peripheries of suspected surface defects are mapped by phase information from complex interface signal. In this way, surface defects are discriminated from fake defects using a parallel spectral domain OCT (SD-OCT) system. Both simulations and experiments are conducted, and these preliminary results demonstrate the advantage of the proposed method to identify glass surface defects.
- Published
- 2015
7. Lens-free all-fiber probe with an optimized output beam for optical coherence tomography
- Author
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Jianrong Qiu, Chen Zhiyan, Zhihua Ding, Yi Shen, and Wen Bao
- Subjects
Beam diameter ,Optical fiber ,Multi-mode optical fiber ,Materials science ,medicine.diagnostic_test ,business.industry ,02 engineering and technology ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,law.invention ,010309 optics ,Lens (optics) ,020210 optoelectronics & photonics ,Optics ,Optical coherence tomography ,law ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,Light beam ,Insertion loss ,business ,Beam (structure) - Abstract
A high-efficiency lensless all-fiber probe for optical coherence tomography (OCT) is presented. The probe is composed of a segment of large-core multimode fiber (MMF), a segment of tapered MMF, and a length of single-mode fiber (SMF). A controllable output beam can be designed by a simple adjustment of its probe structure parameters (PSPs), instead of the selection of fibers with different optical parameters. A side-view probe with a diameter of 340 μm and a rigid length of 6.37 mm was fabricated, which provides an effective imaging range of ∼0.6 mm with a full width at half-maximum beam diameter of less than 30 μm. The insertion loss of the probe was measured to be 0.81 dB, ensuring a high sensitivity of 102.25 dB. Satisfactory images were obtained by the probe-based OCT system, demonstrating the feasibility of the probe for endoscopic OCT applications.
- Published
- 2017
8. Motion correction using overlapped data correlation based on a spatial-spectral encoded parallel optical coherence tomography
- Author
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Peng Li, Wen Bao, Xiaoping Wang, Zhihua Ding, Chen Zhiyan, and Yi Shen
- Subjects
medicine.diagnostic_test ,Computer science ,Image quality ,business.industry ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,Data correlation ,Motion (geometry) ,02 engineering and technology ,Lateral resolution ,Motion correction ,021001 nanoscience & nanotechnology ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,010309 optics ,Optics ,Optical coherence tomography ,Motion artifacts ,0103 physical sciences ,medicine ,0210 nano-technology ,business ,Preclinical imaging - Abstract
This paper presents an approach to remove motion artifacts based on a spatial-spectral encoded parallel OCT (SSE-POCT) system, where encoded rectangular illumination is employed. Motion artifacts within a B-scan are avoided due to parallel detection intrinsic to parallel OCT, while those between successive B-scans are estimated and corrected by a proposed overlapped data correlation (ODC) algorithm. To preserve axial resolution, decoded B-scan corresponding to complete spectrum is stitched from successive encoded B-scans after motion correction. Imaging is conducted on several samples under preset motion trajectories, and OCT images with unnoticed motion artifacts and well-preserved resolutions are reconstructed. The approach based on the developed SSE-POCT system and the proposed ODC algorithm for motion correction can be applicable for in vivo imaging where uncontrolled motion is usually unavoidable.
- Published
- 2017
9. High-sensitive and broad-dynamic-range quantitative phase imaging with spectral domain phase microscopy
- Author
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Yang Ni, Zhao Chen, Yan Yangzhi, Chen Zhiyan, Zhihua Ding, and Yi Shen
- Subjects
medicine.medical_specialty ,Materials science ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,Phase (waves) ,Models, Biological ,Sensitivity and Specificity ,Domain (software engineering) ,Optics ,Optical coherence tomography ,Onions ,medicine ,Microscopy, Phase-Contrast ,Optical path length ,medicine.diagnostic_test ,business.industry ,Dynamic range ,Reproducibility of Results ,Equipment Design ,Image Enhancement ,Atomic and Molecular Physics, and Optics ,Interference microscopy ,Spectral imaging ,Equipment Failure Analysis ,business ,Phase retrieval ,Algorithms - Abstract
Spectral domain phase microscopy for high-sensitive and broad-dynamic-range quantitative phase imaging is presented. The phase retrieval is realized in the depth domain to maintain a high sensitivity, while the phase information obtained in the spectral domain is exploited to extend the dynamic range of optical path difference. Sensitivity advantage of phase retrieved in the depth domain over that in the spectral domain is thoroughly investigated. The performance of the proposed depth domain phase based approach is illustrated by phase imaging of a resolution target and an onion skin.
- Published
- 2013
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