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 ◽  
...  
2016 ◽  
Vol 2 (11) ◽  
pp. e1600370 ◽  
Author(s):  
Amaury Badon ◽  
Dayan Li ◽  
Geoffroy Lerosey ◽  
A. Claude Boccara ◽  
Mathias Fink ◽  
...  

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.


2009 ◽  
Vol 02 (01) ◽  
pp. 117-122 ◽  
Author(s):  
TONG WU ◽  
ZHIHUA DING ◽  
MINGHUI CHEN ◽  
LEI XU ◽  
GUOHUA SHI ◽  
...  

A swept-source optical coherence tomography (SSOCT) system based on a high-speed scanning laser source at center wavelength of 1320 nm and scanning rate of 20 kHz is developed. The axial resolution is enhanced to 8.3 μm by reshaping the spectrum in frequency domain using a window function and a wave number calibration method based on a Mach-Zender Interferometer (MZI) integrated in the SSOCT system. The imaging speed and depth range are 0.04 s per frame and 3.9 mm, respectively. The peak sensitivity of the SSOCT system is calibrated to be 112 dB. With the developed SSOCT system, optical coherence tomography (OCT) images of human finger tissue are obtained which enable us to view the sweat duct (SD), stratum corneum (SC) and epidermis (ED), demonstrating the feasibility of the SSOCT system for in vivo biomedical imaging.


2020 ◽  
Vol 10 (14) ◽  
pp. 4936
Author(s):  
Pingping Jia ◽  
Hong Zhao ◽  
Yuwei Qin

A high-speed, high-resolution swept-source optical coherence tomography (SS-OCT) is presented for focusing lens imaging and a k-domain uniform algorithm is adopted to find the wave number phase equalization. The radius of curvature of the laser focusing lens was obtained using a curve-fitting algorithm. The experimental results demonstrate that the measuring accuracy of the proposed SS-OCT system is higher than the laser confocal microscope. The SS-OCT system has great potential for surface topography measurement and defect inspection of the focusing lens.


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