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Tang Y, Gao W. Effects of orientation deviation of a beam splitter and a reference mirror on the stability of a two-interferometer-based handheld FFOCT imaging probe. APPLIED OPTICS 2021; 60:5942-5952. [PMID: 34263816 DOI: 10.1364/ao.428454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 06/14/2021] [Indexed: 06/13/2023]
Abstract
In this work, we present a handheld full-field optical coherence tomography (FFOCT) system based on a series connection of two interferometers: the Michelson interferometer is used as a compensation part and the Fizeau interferometer is used as a detection part. Owing to the common-path arrangement of the Fizeau interferometer, this handheld FFOCT system has a compact detection arm and is insensitive to the external disturbance. A high-output halogen lamp and high NA microscope objective contribute to achieving the spatial resolution of 0.7µm×0.5µm (transverse × axial). Low imaging stability is caused by an extremely short coherence length. We found that to generate en face images with high quality and high stability using a probe with an extremely short coherence length, the range of deviation of the orientation of the beam splitter must be less than 1°, and the range of orientation deviation of the mirror in the Michelson interferometer corresponds to the displacement between the two field stop images at a distance not to exceed 10 µm.
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Li K, Liang W, Yang Z, Liang Y, Wan S. Robust, accurate depth-resolved attenuation characterization in optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2020; 11:672-687. [PMID: 32206392 PMCID: PMC7041483 DOI: 10.1364/boe.382493] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 12/21/2019] [Accepted: 12/23/2019] [Indexed: 05/06/2023]
Abstract
Depth-resolved optical attenuation coefficient is a valuable tissue parameter that complements the intensity-based structural information in optical coherent tomography (OCT) imaging. Herein we systematically analyzed the under- and over-estimation bias of existing depth-resolved methods when applied to real biological tissues, and then proposed a new algorithm that remedies these issues and accommodates general OCT data that contain incomplete decay and noise floor, thereby affording consistent estimation accuracy for practical biological samples of different scattering properties. Compared with other algorithms, our method demonstrates remarkably improved estimation accuracy and numerical robustness, as validated via numerical simulations and on experimental OCT data obtained from both silicone-TiO2 phantoms and human ventral tongue leukoplakia samples.
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Affiliation(s)
- Kaiyan Li
- School of Biological Science & Medical Engineering, Southeast University, Nanjing, Jiangsu 210096, China
- Equal contribution
| | - Wenxuan Liang
- Depart of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21205, USA
- Currently with the Department of Biomedical Engineering, Columbia University, New York, New York 10027, USA
- Equal contribution
| | - Zihan Yang
- Institute of Modern Optics, Nankai University, Tianjin 300350, China
| | - Yanmei Liang
- Institute of Modern Optics, Nankai University, Tianjin 300350, China
| | - Suiren Wan
- School of Biological Science & Medical Engineering, Southeast University, Nanjing, Jiangsu 210096, China
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Liu YZ, South FA, Xu Y, Carney PS, Boppart SA. Computational optical coherence tomography [Invited]. BIOMEDICAL OPTICS EXPRESS 2017; 8:1549-1574. [PMID: 28663849 PMCID: PMC5480564 DOI: 10.1364/boe.8.001549] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 02/09/2017] [Accepted: 02/10/2017] [Indexed: 05/18/2023]
Abstract
Optical coherence tomography (OCT) has become an important imaging modality with numerous biomedical applications. Challenges in high-speed, high-resolution, volumetric OCT imaging include managing dispersion, the trade-off between transverse resolution and depth-of-field, and correcting optical aberrations that are present in both the system and sample. Physics-based computational imaging techniques have proven to provide solutions to these limitations. This review aims to outline these computational imaging techniques within a general mathematical framework, summarize the historical progress, highlight the state-of-the-art achievements, and discuss the present challenges.
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Affiliation(s)
- Yuan-Zhi Liu
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, USA
| | - Fredrick A. South
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, USA
| | - Yang Xu
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, USA
| | - P. Scott Carney
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, USA
| | - Stephen A. Boppart
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, USA
- Departments of Bioengineering and Internal Medicine, University of Illinois at Urbana-Champaign, USA
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Rajai P, Schriemer H, Amjadi A, Munger R. Simultaneous measurement of refractive index and thickness of multilayer systems using Fourier domain optical coherence tomography, part 2: implementation. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:15003. [PMID: 28150009 DOI: 10.1117/1.jbo.22.1.015003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 01/03/2017] [Indexed: 06/06/2023]
Abstract
We introduce a theoretical method for simultaneous measurement of refractive index and thickness of multilayer systems using Fourier domain optical coherence tomography (FD-OCT) without any auxiliary arrangement. The input data to the formalism are the FD-OCT measured optical path lengths (OPLs) and properly selected spectral components of FD-OCT interference spectrum. The outputs of the formalism can be affected significantly by uncertainty in measuring the OPLs. An optimization method is introduced to deal with the relatively large amount of uncertainty in measured OPLs and enhance the final results. Simulation result shows that by using the optimization method, indices can be extracted with the absolute error ? 0.001 for transparent biological samples having indices < 1.55 .
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Affiliation(s)
- Payman Rajai
- University of Ottawa, Physics Department, 150 Louis Pasteur, Ottawa, Ontario K1N 6N5, Canada
| | - Henry Schriemer
- University of Ottawa, Physics Department, 150 Louis Pasteur, Ottawa, Ontario K1N 6N5, CanadabUniversity of Ottawa, School of Electrical Engineering and Computer Science, 25 Templeton Avenue, Ottawa, Ontario K1N 6N5, Canada
| | - Ahmad Amjadi
- Sharif University of Technology, Physics Department, P.O. Box 11155-9161, Tehran, Iran
| | - Rejean Munger
- University of Ottawa, Physics Department, 150 Louis Pasteur, Ottawa, Ontario K1N 6N5, Canada
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Rajai P, Schriemer H, Amjadi A, Munger R. Simultaneous measurement of refractive index and thickness of multilayer systems using Fourier domain optical coherence tomography, part 1: theory. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:15002. [PMID: 28130924 DOI: 10.1117/1.jbo.22.1.015002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 01/03/2017] [Indexed: 06/06/2023]
Abstract
We introduce a theoretical framework for simultaneous refractive index and thickness measurement of multilayer systems using the Fourier domain optical coherence tomography (FD-OCT) system without any previous information about the item under investigation. The input data to the new formalism are the FD-OCT measured optical path lengths and properly selected spectral components of the FD-OCT interference spectrum. No additional arrangement, reference reflector, or mechanical scanning is needed in this approach. Simulation results show that the accuracy of the extracted parameters depends on the index contrast of the sample while it is insensitive to the sample’s thickness profile. For transparent biological samples with smooth interfaces, when the object is in an aqueous medium and has indices < 1.55 , this method can extract indices and thicknesses with the absolute error ? 0.001 .
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Affiliation(s)
- Payman Rajai
- University of Ottawa, Physics Department, 150 Louis Pasteur, Ottawa, Ontario K1N 6N5, Canada
| | - Henry Schriemer
- University of Ottawa, Physics Department, 150 Louis Pasteur, Ottawa, Ontario K1N 6N5, CanadabUniversity of Ottawa, School of Electrical Engineering and Computer Science, Ottawa, Ontario K1N 6N5, Canada
| | - Ahmad Amjadi
- Sharif University of Technology, Physics Department, P.O. Box: 11155-9161, Tehran, Iran
| | - Rejean Munger
- University of Ottawa, Physics Department, 150 Louis Pasteur, Ottawa, Ontario K1N 6N5, Canada
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Kumar A, Drexler W, Leitgeb RA. Numerical focusing methods for full field OCT: a comparison based on a common signal model. OPTICS EXPRESS 2014; 22:16061-78. [PMID: 24977860 DOI: 10.1364/oe.22.016061] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
In this paper a theoretical model of the full field swept source (FF SS) OCT signal is presented based on the angular spectrum wave propagation approach which accounts for the defocus error with imaging depth. It is shown that using the same theoretical model of the signal, numerical defocus correction methods based on a simple forward model (FM) and inverse scattering (IS), the latter being similar to interferometric synthetic aperture microscopy (ISAM), can be derived. Both FM and IS are compared quantitatively with sub-aperture based digital adaptive optics (DAO). FM has the least numerical complexity, and is the fastest in terms of computational speed among the three. SNR improvement of more than 10 dB is shown for all the three methods over a sample depth of 1.5 mm. For a sample with non-uniform refractive index with depth, FM and IS both improved the depth of focus (DOF) by a factor of 7x for an imaging NA of 0.1. DAO performs the best in case of non-uniform refractive index with respect to DOF improvement by 11x.
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