江苏大学 流体机械工程技术研究中心,江苏 镇江 212013
微颗粒操控技术以其控制精确,成本低及简洁高效的特点, 在生物医学工程和微纳米器件制造领域有广阔的应用前景。传统操控方法对无磁性、无导电性及大密度固体微颗粒的操控存在不足。因此, 该文提出一种基于压电悬臂梁低频振动的微颗粒操控系统, 利用流场底部流动实现微颗粒的聚集。聚集显微实验表明, 压电振子的低频振动激发流场底部流动, 使培养皿底部的球型氧化铝颗粒向目标区域移动和聚集, 并在122 s时达到稳定状态。对试验结果进行图像处理, 结果表明, 微颗粒稳定聚集后的聚集面积为79 405 μm2。该操控方法可实现大密度微颗粒的聚集, 且聚集范围大, 可为微纳器件制造提供参考。
微流控技术 压电悬臂梁 压电效应 微颗粒操控 悬臂梁振动 microfluidic technology piezoelectric cantilever beam piezoelectric effect microparticle manipulation cantilever beam vibration
1 中国科学院新疆理化技术研究所 新疆爆炸物安全科学自治区重点实验室，乌鲁木齐 830000
2 中国科学院大学 材料与光电研究中心，北京 100049
非制式爆炸物因原料易得、破坏性大等特点，已成为暴恐分子施爆的首选方式。目前，国内外针对光学传感2，4，6-三硝基甲苯、2，4-二硝基甲苯等制式爆炸物的研究已经相对成熟，而对于非制式爆炸物，因其具有与制式爆炸物完全不同的本征特性，如多为不挥发离子晶体、分子构型差异巨大等，难以通过光学传感制式爆炸物的原理对其分析与识别，成为国际反恐的棘手难题。因此，针对非制式爆炸物的特性，设计特异性光学传感材料、提出光学信号增强策略、建立现场识别超痕量非制式爆炸物的有效方案，是实现追踪非制式爆炸物源头、截断非制式爆炸物转移路径与炸后残留定性分析的迫切需求。本文从光学传感的本质出发，系统总结了传感材料的设计方法和比色/荧光传感非制式爆炸物模式的发展趋势，旨在为光学传感非制式爆炸物领域提供思路和借鉴。
爆炸物 单颗粒 比色 荧光 光学传感 Explosive Single microparticle Colorimetric Fluorescence Optical sensing
暨南大学纳米光子学研究院, 广东 广州 511443
以光纤通信为代表的光纤科学与技术的发展取得了辉煌成就, 以光纤传感为代表的光纤科学与技术的研究已延伸到社会发展和人们生活的各个方面, 以光纤为基础的各种新型微纳结构光子器件不断被设计和制作成功, 新的应用领域和潜力不断被挖掘。将微纳光纤探针应用到光镊领域, 不仅可以操控数量庞大的微粒, 还可以精确操控单个微粒, 这在微粒组装、筛选等领域有重要应用。将光纤探针应用到生物细胞的操控中, 能给研究细胞之间的相互作用提供新思路。
光纤探针 微粒 光捕获 光学操控 生物细胞 fiber probers microparticle optical trapping optical manipulation biological cells
Author Affiliations
Abstract
1 Departamento de Física, Universidade Federal de Pernambuco, Recife-PE 50670-901, Brazil
2 Instituto de Física, Universidade Federal de Goiás, Goiânia-GO 74001-970, Brazil
The confocal microscopy technique was applied for nonlinear optical characterization of single β-barium-borate (β-BBO) nanocrystals. The experimental setup allows measurements of the laser polarization-selective second-harmonic (SH) generation, and the results can be used to determine the nanocrystals’ c-axis orientation, as well as to obtain information about their second-order susceptibility χ(2). The dependence of the SH signal on the laser polarization allowed the discrimination of individual particles from aggregates. The data were fitted using a model that takes into account the BBO properties and the experimental setup characteristics considering (i) the electrostatic approximation, (ii) the effects of the microscope objective used to focus the light on the sample in an epi-geometry configuration, and (iii) the symmetry of χ(2) for the β-BBO nanocrystals. A signal at the third-harmonic frequency was also detected, but it was too weak to be studied in detail.
190.3970 Microparticle nonlinear optics 180.4315 Nonlinear microscopy Chinese Optics Letters
2018, 16(4): 041902
广东医学院信息工程学院, 广东 东莞 523808
通过热熔拉法将单模光纤拉制成亚微米尺寸的光纤，并借助光学显微镜的定位作用，在亚微米光纤的特定位置沉积金纳米棒（长度和中截面直径分别为80 nm和20 nm）。利用光纤倏逝波激发金纳米棒的局域表面等离波子共振（LSPR）。由于强的共振吸收和光热效应，当激光功率增加到30 mW时，亚微米光纤上沉积金纳米棒的位置会产生一个微米尺寸的气泡，激光在该位置将被等离波子共振吸收和气泡散射掉，在气泡后面位置的光纤中观察不到光的传输。靠近光纤的900 nm的聚苯乙烯颗粒被倏逝波所产生的梯度力捕获到光纤表面，并在散射力的作用下沿着光的传播方向运动，当颗粒运动到气泡位置时，将会停止向前运动。该技术可用于微米颗粒的定点输送。
光纤光学 定点输送 气泡 微颗粒 激光与光电子学进展
2013, 50(7): 070602
Author Affiliations
Abstract
The finding of nonlinear nanometric-sized probes is of key importance for the development of nonlinear microscopy in physical as well as biological sciences. We isolate nonlinear KTiOPO4 nanocrystals and study them by second-harmonic generation microscopy (SHGM) and atomic force microscopy (AFM) independently. With both polarization analysis and defocused imaging of the emitted second harmonic field, we extract the Euler angles of the crystalline axes of a single nanocrystal. A balanced coherent optical homodyne detection shows the coherent nature of the nanocrystal nonlinear emission and allows a phase measurement of the emitted second-harmonic field. These features make the KTiOPO4 nanocrystal a good candidate for a vectorial probe of electromagnetic near fields.
190.3970 Microparticle nonlinear optics 170.5810 Scanning microscopy 160.4330 Nonlinear optical materials Chinese Optics Letters
2008, 6(1): 0164
Author Affiliations
Abstract
1 National Key Laboratory of Tunable Laser Technology, Institute of Opto-Electronics, Harbin Institute of Technology, Harbin 150001
2 Shenyang Normal University, Shenyang 110034
3 College of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093
The third-order nonlinearities of PbS nano-belts have been investigated using the Z-scan technique with nanosecond laser pulses at 532 nm. The effect of the PbS semiconductor nano-belt size on the third-order optical nonlinearities and optical limiting properties was studied. We found that the nonlinear absorption and nonlinear refraction have not strict dependence on the nano-belt size under our investigated condition, but their optical limiting behavior is different. The optical limiting mechanism of materials is discussed.
190.3970 Microparticle nonlinear optics 190.4400 Nonlinear optics, materials 190.5970 Semiconductor nonlinear optics including MQW Chinese Optics Letters
2005, 3(0s): 248
Author Affiliations
Abstract
1 Advanced Photonics Center, Southeast University, Nanjing 210096
2 National Laboratory of Molecular and Biomolecular Electronics, Southeast University, Nanjing 210096
3 Department of Electrical Engineering, Aichi Institute of Technology, Toyota 470-0392, Japan
4 Department of Information Network Engineering, Aichi Institute of Technology, Toyota 470-0392, Japan
Hyper-Rayleigh scattering (HRS) technique has been used to study second-order nonlinear optical (NLO) properties of some centrosymmetric metal and semiconductor nanoparticles. All the samples display big "per particle" first hyperpolarizabilities 'beta'_(par). For centrosymmetric particles the contributions of multipolar radiations are very important to their second-order NLO responses. The metal nanoparticles show 'beta'_(par) two orders greater than that of the semiconductor ones, which can be explained by the enhancement of surface plasma resonance (SPR). It also reveals that the HRS signals are very sensitive to metal nanoparticles' aggregation.
190.4410 Nonlinear optics, parametric processes 190.3970 Microparticle nonlinear optics 270.4180 Multiphoton processes 300.6410 Spectroscopy, multiphoton Chinese Optics Letters
2005, 3(0s): 125
