Author Affiliations
Abstract
1 Boston University, Department of Electrical and Computer Engineering, Boston, Massachusetts, United States
2 Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
Improving the spatial resolution of a fluorescence microscope has been an ongoing challenge in the imaging community. To address this challenge, a variety of approaches have been taken, ranging from instrumentation development to image postprocessing. An example of the latter is deconvolution, where images are numerically deblurred based on a knowledge of the microscope point spread function. However, deconvolution can easily lead to noise-amplification artifacts. Deblurring by postprocessing can also lead to negativities or fail to conserve local linearity between sample and image. We describe here a simple image deblurring algorithm based on pixel reassignment that inherently avoids such artifacts and can be applied to general microscope modalities and fluorophore types. Our algorithm helps distinguish nearby fluorophores, even when these are separated by distances smaller than the conventional resolution limit, helping facilitate, for example, the application of single-molecule localization microscopy in dense samples. We demonstrate the versatility and performance of our algorithm under a variety of imaging conditions.
image deblurring microscopy bio-imaging image reconstruction optical resolution Advanced Photonics
2023, 5(6): 066004
1 山西大学光电研究所, 量子光学与光量子器件国家重点实验室山西 太原 030006
2 山西大学, 极端光学协同创新中心山西 太原 030006
本文设计并搭建了一套激励光和超声探测器对向共轴共焦的具备亚细胞尺度成像分辨率和毫米级成像深度的光学分辨率光声显微成像（OR-PAM：Optical-resolution photoacoustic microscopy）系统。与基于多纵模脉冲激光激励的光声成像系统相比，使用自制的单纵模纳秒532 nm 脉冲激励光源，将光声探测的信号强度提高了1.35 倍，测得成像系统的轴向分辨率为18 m，横向分辨率为8 m，成像深度为1:54 mm，成像深度-横向空间分辨率比达192.5。利用研制的OR-PAM 系统对嵌有碳纤维丝的仿体样品以及活体小鼠的耳朵进行成像，获得了高分辨率的图像。
单纵模纳秒脉冲激光 光学分辨率 光声显微成像 亚细胞结构尺度 single longitudinal mode nanosecond pulsed laser optical resolution photoacoustic microscopy subcellular structure
Author Affiliations
Abstract
1 City University of Hong Kong, Department of Biomedical Engineering, Kowloon, Hong Kong SAR, China
2 City University of Hong Kong, Shenzhen Research Institute, Shenzhen, China
Optical-resolution photoacoustic microscopy (OR-PAM) has been developed for anatomical, functional, and molecular imaging but usually requires multiple scanning for different contrasts. We present five-wavelength OR-PAM for simultaneous imaging of hemoglobin concentration, oxygen saturation, blood flow speed, and lymphatic vessels in single raster scanning. We develop a five-wavelength pulsed laser via stimulated Raman scattering. The five pulsed wavelengths, i.e., 532, 545, 558, 570, and 620 / 640 nm, are temporally separated by several hundreds of nanoseconds via different optical delays in fiber. Five photoacoustic images at these wavelengths are simultaneously acquired in a single scanning. The 532- and 620 / 640-nm wavelengths are used to image the blood vessels and dye-labeled lymphatic vessels. The blood flow speed is measured by a dual-pulse method. The oxygen saturation is calculated and compensated for by the Grüneisen-relaxation effect. In vivo imaging of hemoglobin concentration, oxygen saturation, blood flow speed, and lymphatic vessels is demonstrated in preclinical applications of cancer detection, lymphatic clearance monitoring, and functional brain imaging.
optical-resolution photoacoustic microscopy stimulated Raman scattering single-shot multi-contrast microscopy early cancer detection Advanced Photonics
2021, 3(1): 016002
1 中国科学院上海光学精密机械研究所激光与光电子功能材料中心, 上海 201800
2 中国科学院大学, 北京 100049
3 中国科学院上海高等研究院宏观量子现象与应用中心, 上海 201210
4 中国科学院化学研究所光化学实验室, 北京 100190
利用开环态双光子吸收转化荧光光谱、荧光淬灭光谱等探究了二芳基乙烯的光学记录特性及参数, 得到其非线性吸收系数为3.46×10-13 m/W, 双光子吸收转化的阈值功率密度为107.36 GW/cm2, 荧光淬灭的阈值功率密度为2.89 GW/cm2。基于所得到的测试参数, 理论计算出其在超分辨光存储中的分辨率可达60.0 nm, 并设计了一种基于二芳基乙烯的双光子双光束超分辨光存储信息记录和读出方法。研究结果表明, 二芳基乙烯具有光诱导-光抑制、非线性吸收及荧光淬灭等特性, 是一种优异的超分辨光存储备选材料。
材料 光数据存储 光学分辨率 超分辨光学记录 光诱导-光抑制 二芳基乙烯
1 江西科技师范大学光电子与通信省重点实验室, 江西 南昌 330038
2 湖南工业大学理学院, 湖南 株洲 412000
3 广州多浦乐电子科技有限公司, 广东 广州 510663
采用具有价格低、体积小、寿命长、重复率高等优点的脉冲激光二极管，搭建了一套光学分辨模式的小型化光声显微成像系统，并获得了碳纤维原丝和微血管网络样品的光声显微成像。实验中，脉冲激光二极管光源由三维平移台驱动做C型扫描逐点激发，产生的光声信号由1-3复合材料超宽带超声传感器接收。实验表明，接收的光声数据信噪比可达约11 dB，该系统的横向分辨率在上一代系统样机500 μm的基础上提高到1.5 μm，有望发展成为一种低成本、实时、便携式的高分辨率光声显微成像技术。
生物光学 光声显微成像 激光二极管 光学分辨 中国激光
2014, 41(10): 1004001
Author Affiliations
Abstract
1 School of Physics and Telecom Engineering, South China Normal University Guangzhou 510006, P. R. China
2 Laboratory of Quantum Information Technology, South China Normal University IMOT, Guangzhou 510006, P. R. China
We demonstrate the feasibility of simultaneous multi-probe detection for an optical-resolution photoacoustic microscopy (OR-PAM) system. OR-PAM has elicited the attention of biomedical imaging researchers because of its optical absorption contrast and high spatial resolution with great imaging depth. OR-PAM allows label-free and noninvasive imaging by maximizing the optical absorption of endogenous biomolecules. However, given the inadequate absorption of some biomolecules, detection sensitivity at the same incident intensity requires improvement. In this study, a modulated continuous wave with power density less than 3mW/cm2 (1/4 of the ANSI safety limit) excited the weak photoacoustic (PA) signals of biological cells. A microcavity transducer is developed based on the bulk modulus of gas five orders of magnitude lower than that of solid; air pressure variation is inversely proportional to cavity volume at the same temperature increase. Considering that a PA wave expands in various directions, detecting PA signals from different positions and adding them together can increase detection sensitivity and signal-to-noise ratio. Therefore, we employ four detectors to acquire tiny PA signals simultaneously. Experimental results show that the developed OR-PAM system allows the label-free imaging of cells with weak optical absorption.
Multi-probe label-free optical-resolution photoacoustic microscopy Journal of Innovative Optical Health Sciences
2013, 6(3): 1350027
1 华南农业大学理学院，广州 510642
2 华南师范大学物理系，广州 510631
通过与双光子荧光共焦成像过程比较，研究了非线性二次谐波的强度脉冲响应函数并对它进行频域分析，获得了横向、纵向截止频率和通频带．研究结果表明：二次谐波共焦成像具有更高的分辨率．
共焦显微镜 二次谐波 频域 分辨率 Confocal microscope Second-harmonic wave Frequency domain Optical resolution
State Key Lab. of Precision Measurement Technology and Instruments, Dept. of Precision Instruments, Tsinghua University, Beijing 100084, CHN
