北京大学未来技术学院,国家生物医学成像科学中心,北京 100871
相干拉曼散射(CRS)技术作为一种重要的无标记化学成像技术,通过相干激发分子协同振动对拉曼散射信号进行增益,显著地提高了成像速度,广泛应用于材料学、生物化学、肿瘤诊断、药代动力学等领域。超快脉冲激光器的出现实现了亚皮秒持续时间的脉冲输出,使得通过脉冲激发实现大量振动模式的同步相干激发成为新的CRS实现途径。从相干拉曼散射基本原理出发,介绍时域相干拉曼散射的主要实现途径,着重讨论时域受激拉曼散射(SRS)和时域相干反斯托克斯拉曼散射(CARS)的最新进展与应用。
拉曼光谱技术 相干拉曼散射 受激拉曼散射 相干反斯托克斯拉曼散射 时域 频域 激光与光电子学进展
2024, 61(6): 0618007
1 上海理工大学光电信息与计算机工程学院,上海 200093
2 复旦大学物理学系表面物理国家重点实验室,上海 200433
水是生物体中含量最多的一种物质,了解生物体内水的分布对于理解水的生理功能来说至关重要。相干反斯托克斯拉曼散射(CARS)作为一种非侵入的成像技术,能够对生物体内的水分子进行实时且免标记的成像。因此,设计并搭建了用于水的CARS被动同步光纤激光器系统,该被动同步系统由掺铒和掺镱锁模光纤激光器构成,通过将主脉冲注入到从激光器腔内引入非对易相移,进而实现无源同步,同步失配距离达到347 μm。结合功率放大技术、倍频技术和脉冲压缩技术,双路输出平均功率分别为146 mW和2 W,脉冲宽度分别为146.0 fs和9.1 ps。使用所搭建的同步光源在3156 cm-1处对新鲜小鼠耳朵组织进行CARS成像,成像效果良好。该同步光纤光源有望推动CARS技术在快速、实时、高效病理学检测领域的应用。
光纤激光器 被动同步 非线性光学 相干反斯托克斯拉曼散射 光学学报
2023, 43(23): 2336001
Author Affiliations
Abstract
1 Integrative Oncology Department – Imaging Unit, BC Cancer Research Institute, Vancouver, BC, Canada
2 Department of Dermatology and Skin Science, University of British Columbia and Vancouver Coastal Health Research Institute, Vancouver, BC, Canada
Multi-photon microscopy (MPM) and coherent anti-Stokes Raman scattering (CARS) are two advanced nonlinear optical imaging techniques, which provide complementary information and have great potential in combination for noninvasive in vivo biomedical applications. This paper provides a detailed discussion of the basics, development and applications of these technologies for in vivo skin research, covering the following topics: The principle and advantage of MPM and CARS, instrumentation development for in vivo applications, MPM and CARS of normal skin, application of MPM and CARS in skin cancer and disease diagnosis; application of MPM in skin disease intervention, i.e., imaging guided two-photon photothermolysis.Multi-photon microscopy (MPM) and coherent anti-Stokes Raman scattering (CARS) are two advanced nonlinear optical imaging techniques, which provide complementary information and have great potential in combination for noninvasive in vivo biomedical applications. This paper provides a detailed discussion of the basics, development and applications of these technologies for in vivo skin research, covering the following topics: The principle and advantage of MPM and CARS, instrumentation development for in vivo applications, MPM and CARS of normal skin, application of MPM and CARS in skin cancer and disease diagnosis; application of MPM in skin disease intervention, i.e., imaging guided two-photon photothermolysis.
Nonlinear microscopy multiphoton microscopy coherent anti-Stokes Raman scattering microscopy skin skin cancer multiphoton therapy Journal of Innovative Optical Health Sciences
2023, 16(1): 2230018
大连理工大学光电工程与仪器科学学院, 辽宁 大连 116000
由于塑料工业的发展, 微塑料成为一种主要的环境污染物。 它在自然界中不易降解, 对人类的生存环境及健康都存在不可忽视的潜在危险。 因此, 环境中微塑料的检测和分析, 成为了近年来研究的热点问题。 目前人们大多数采用浮选法、 密度分离法、 离心法等方法提取微塑料, 然后放在显微镜下进行目视观察, 并结合拉曼光谱分析、 傅里叶红外光谱分析、 高光谱成像等方法进行分析鉴别, 这些方法需要较长时间的等待或预处理, 且易受主观因素的影响。 因此提出一种快速、 准确鉴别环境中是否含有微塑料的技术是必要的。 相干反斯托克斯拉曼散射(CARS)光谱成像技术是一种基于化学键振动的非侵入性、 非破坏性且无需特殊标记的实时成像方法, 由此提出使用多通道图像采集(含有白光通道成像及CARS光谱成像)的方法快速、 准确鉴别环境中微塑料的分布。 将直径为10 μm的聚苯乙烯微球掺入到收集的海水及沙子中, 模拟被微塑料污染的海水及沙子, 在不作任何处理的情况下对海水及沙子进行多通道图像采集。 通过多通道图像采集可以快速直观地检测到海水中聚苯乙烯微球的分布。 在对沙子中的聚苯乙烯微球进行多通道图像采集的同时, 采用拉曼光谱检测与之对照。 在拉曼光谱检测中, 聚苯乙烯微球的信号易受沙子荧光信号干扰, 且只有在激光聚焦在聚苯乙烯存在的位置时, 才能检测到微弱的信号。 在多通道图像采集检测中, 可以看到沙子中存在的聚苯乙烯微球, 且采用形态学分析中先腐蚀后膨胀的开运算算法同时结合中值滤波的算法后, 可以实现突出显示聚苯乙烯信号的目的。 多通道图像采集可以在无任何预处理的情况下检测出海水及沙子中的微塑料, 具有快速简便的优势, 对实现环境中微塑料的检测具有一定的潜在应用价值。
拉曼光谱 相干反斯托克斯拉曼散射 微塑料 聚苯乙烯 Raman Spectrum Coherent anti-Stokes Raman scattering Microplastics Polystyrene 光谱学与光谱分析
2022, 42(4): 1022
上海理工大学 光电信息与计算机工程学院, 上海 200093
实验展示了一种双色被动同步的全保偏光纤激光器, 该激光器可产生宽带光谱有望用于相干反斯托克斯拉曼散射光谱探测。激光器由掺镱与掺铒的光纤激光器组成, 采用注入式被动同步的方式, 在150 μm腔长失配距离内获得稳定的被动同步状态。其中掺铒激光器由高非线性光纤光谱展宽至1000~1700 nm, 与掺镱激光器输出光在空间中合束后通过和频晶体产生和频信号。被动同步双色光纤激光器可作为相干反斯托克斯拉曼散射的稳定、宽光谱探测超快光源, 有望实现宽光谱多个拉曼峰同时探测。
光纤激光器 激光同步 超连续谱产生 相干反斯托克斯拉曼散射 fiber laser laser synchronization supercontinuum generation coherent anti-Stokes Raman scattering
Author Affiliations
Abstract
1 Xi'an Key Laboratory of Intelligent Sensing and Regulation of trans-Scale Life Information, School of Life Science and Technology, Xidian University, Xi'an, Shaanxi 710126, P. R. China
2 Engineering Research Center of Molecular & Neuro Imaging of the Ministry of Education, Xidian University, Xi'an, Shaanxi 710126, P. R. China
3 Shaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital), Affliated Guangren Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an 710004, P. R. China
Coherent anti-Stokes Raman scattering (CARS) microscopy can resolve the chemical components and distribution of living biological systems in a label-free manner and is favored in several disciplines. Current CARS microscopes typically use bulky, high-performance solid-state lasers, which are expensive and sensitive to environmental changes. With their relatively low cost and environmental sensitivity, supercontinuum fiber (SF) lasers with a small footprint have found increasing use in biomedical applications. Upon these features, in this paper, we homebuilt a lowcost CARS microscope based on a SF laser module (scCARS microscope). This SF laser module is specially customized by adding a time-synchronized seed source channel to the SF laser to form a dual-channel output laser. The performance of the scCARS microscope is evaluated with dimethyl sulfoxide, whose results confirm a spatial resolution of better than 500 nm and a detection sensitivity of millimolar concentrations. The dual-color imaging capability is further demonstrated by imaging different species of mixed microspheres. We finally explore the potential of our scCARS microscope by mapping lipid droplets in different cancer cells and corneal stromal lenses.
Coherent anti-Stokes Raman scattering supercontinuum fiber laser lipid mapping cancer cell Journal of Innovative Optical Health Sciences
2022, 15(4): 2250024
Author Affiliations
Abstract
1 Zhejiang University, State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Hangzhou, China
2 Shanxi University, Collaborative Innovation Center of Extreme Optics, Taiyuan, China
3 Research Center for Intelligent Chips and Devices, Zhejiang Lab, Hangzhou, China
4 Zhejiang University, Ningbo Research Institute, Ningbo, China
Stimulated emission depletion (STED) nanoscopy is one of the most well-developed nanoscopy techniques that can provide subdiffraction spatial resolution imaging. Here, we introduce dual-modulation difference STED microscopy (dmdSTED) to suppress the background noise in traditional STED imaging. By applying respective time-domain modulations to the two continuous-wave lasers, signals are distributed discretely in the frequency spectrum and thus are obtained through lock-in demodulation of the corresponding frequencies. The background signals can be selectively eliminated from the effective signal without compromise of temporal resolution. We used nanoparticle, fixed cell, and perovskite coating experiments, as well as theoretical demonstration, to confirm the effectiveness of this method. We highlight dmdSTED as an idea and approach with simple implementation for improving the imaging quality, which substantially enlarges the versatility of STED nanoscopy.
super-resolution microscopy frequency domain background suppression anti-Stokes excitation Advanced Photonics
2022, 4(4): 046001