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 8.3μm ...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 8.3μm 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.展开更多
The previous methods to measure flow speed by photoacoustic microscopy solely focused on either the transverse or the axial flow component, which did not reflect absolute flow speed. Here, we present absolute flow spe...The previous methods to measure flow speed by photoacoustic microscopy solely focused on either the transverse or the axial flow component, which did not reflect absolute flow speed. Here, we present absolute flow speed maps by combining Doppler bandwidth broadening with volumetric photoacoustic microscopy. Photoacoustic Doppler bandwidth broadening and photoacoustic tomographic images were applied to measure the transverse flow component and the Doppler angle, respectively. Phantom experiments quantitatively demonstrated that ranges of 55° to 90° Doppler angle and 0.5 to 10 mm/s flow speed can be measured. This tomography-assisted method provides the foundation for further measurement in vivo.展开更多
基金supported by the National High Technology Research and Development Program of China(2006AA02Z4E0,2008AA02Z422)Natural Science Foundation of China(60878057,60478040).
文摘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 8.3μm 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.
基金supported by the National Natural Science Foundation of China (Nos. 61822505,11774101,61627827,and 81630046)the Science and Technology Planning Project of Guangdong Province,China(No. 2015B020233016)+2 种基金the China Postdoctoral Science Foundation (No. 2019M652943)the Natural Science Foundation of Guangdong Province,China(No. 2019A1515011399)the Science and Technology Program of Guangzhou (No. 2019050001)
文摘The previous methods to measure flow speed by photoacoustic microscopy solely focused on either the transverse or the axial flow component, which did not reflect absolute flow speed. Here, we present absolute flow speed maps by combining Doppler bandwidth broadening with volumetric photoacoustic microscopy. Photoacoustic Doppler bandwidth broadening and photoacoustic tomographic images were applied to measure the transverse flow component and the Doppler angle, respectively. Phantom experiments quantitatively demonstrated that ranges of 55° to 90° Doppler angle and 0.5 to 10 mm/s flow speed can be measured. This tomography-assisted method provides the foundation for further measurement in vivo.
