激光近场探测传感器在机器人动态避障中的应用

普通传感器在工业机器人应用中,外部环境的不确定性会对机器人目标探测效果造成影响,导致机器人无法精准避障。为此,研究激光近场探测传感器在机器人动态避障中的应用。确立场景环境坐标系,并利用探测传感器探测出障碍物信息。基于此,采用多激光近场传感器信息融合技术,定位探测的障碍物,从中得出障碍决策值,最终根据障碍决策值,制定激光近场探测传感器动态避障行为,完成动态避障。实验结果表明,通过对该传感器开展机器人静态避障测试、动态避障测试,验证了该传感器应用后的避障精准度高。

隐身目标激光近场散射特性研究

采用波束分割法,通过仿真计算各个被照射小面元的激光雷达散射截面(Laser Radar Cross Section,LRCS),并进行叠加,获得目标LRCS。定量分析了隐身目标的激光远场、近场散射特性,可以为激光近距探测系统灵敏度等参数的设计提供依据。

基于光谱特性的高判别准确度激光近场探测传感器研究

激光近场探测是激光测量重要的应用方向之一,尤其是基于距离信息的近场探测系统有着巨大的应用前景。传统的激光近场探测系统只依靠距离信息给出信号,而不判别反射距离信号的物体是否为目标,可能导致误报。基于光谱特性进行目标识别会大大减少激光近场测量系统的误报率,极大提高判别准确度。设计实现了一种单芯片的光谱分析器件,利用半导体技术将光谱元件和光电元件进行单芯片的集成,从而减小了传统光谱分析系统的体积和质量。实验结果表明,该微系统级的光谱分析芯片具有识别既定伪装物体的能力,使得该技术具有在激光近场探测中应用的前景。

基于激光近场辐照的351nm激光诱导熔石英损伤研究

针对351nm激光诱导熔石英样品进行损伤实验。采用激光近场辐照样品,并基于近场辐照的损伤阈值定义方法进行损伤测试。利用带有灰度抑制的分水岭标记分割算法对损伤图像进行损伤区域提取,与相应近场分布进行比较,得到损伤区域边界点对应的局域能量密度即为损伤阈值。这种损伤测试方法简单、快速,有效降低了损伤阈值口径效应,且采用了能够有效去除噪声和抑制图像过分割问题的算法对损伤图像进行处理,使得到的损伤阈值和损伤增长系数有较高的准确性。实验结果表明,脉冲宽度为3.13ns的351nm激光诱导熔石英样品的损伤阈值为2.94J/cm2;在多次辐照样品情况下,熔石英样品出射面的损伤尺寸随着辐照次数的增加呈指数增长,其损伤增长系数为0.32。

基于激光近场和图像分割技术的复合波长诱导熔石英损伤实验研究

在复合波长(波长分别为1053、527、351nm)情况下,利用激光近场对熔石英样品进行损伤实验。设计了一种基于激光近场辐照的损伤阈值定义方法,并利用带有灰度抑制的分水岭标记算法对损伤图像进行损伤区域提取,通过对比损伤图像与相应光束近场能量分布,计算出损伤区域与非损伤区域临界处的光能量密度,即为熔石英样品的损伤阈值。实验结果表明,复合波长激光诱导熔石英损伤是3种波长激光共同作用的结果,但351nm激光对损伤起主要作用,初始损伤阈值为8.22J/cm2;在复合波长激光多次辐照样品的情况下,熔石英样品后表面的损伤成指数形式增长,损伤增长系数为0.59。

催化近场激光热透镜光谱法测定痕量铱

将近场激光热透镜光谱分析法与动力学分析法相结合.基于铱(Ⅳ)催化高碘酸钾氧化耐尔蓝A的动力学反心,建立了催化近场激光热透镜光谱法测定痕量铱的新方法,并探讨了反应机理。结果表明:铱浓度在0.05～2.4μg/L范围内呈线性关系;俭出限为6.2 x 10-12g/mL。应用该方法测定矿样中痕量铱.结果满意。

近场激光热透镜光谱法测定痕量磷的研究

利用He_Ne激光器 ( 6 32 .8nm)观测了孔雀绿_磷钼杂多酸离子缔合物的激光热透镜效应 ,建立了近场激光热透镜光谱法测定痕量磷的新方法 .磷含量在 0～ 80ng/mL范围内与热透镜信号强度成良好的线性关系 ,检出限为1ng/mL.该方法已应用于河水。

针剂中多巴胺的近场激光热透镜光谱法测定

基于多巴胺与四氯苯醌荷移反应 ,建立了近场激光热透镜光谱法测定多巴胺的新方法 ,讨论了测定条件的影响 ;结果表明 ,该法灵敏度高 ,多巴胺质量浓度在0.04～2mg·L-1 范围内与信号强度呈线性关系 ,检出限20μg·L-1;应用于药物制剂中多巴胺的测定 。

激光超衍射加工机理与研究进展

随着纳米科技和微纳电子器件的发展,制造业对微纳加工技术的要求越来越高.激光加工技术是一种绿色先进制造技术,具有巨大的发展潜力,己广泛应用于不同的制造领域.为实现低成本、高效率、大面积尤其是高精度的激光微纳加工制造,研究和发展激光超衍射加工技术具有十分重要的科学意义和应用价值.本文首先阐述了基于非线性效应的远场激光直写超衍射加工技术的原理与国内外发展状况,包括激光烧蚀加工技术、激光诱导改性加工技术和多光子光聚合加工技术等;然后介绍了几种基于倏逝波的近场激光超衍射加工技术,包括扫描近场光刻技术、表面等离子激元光刻技术等新型超衍射激光近场光刻技术的机理与研究进展;最后对激光超衍射加工中存在的问题及未来发展方向进行了讨论.

小型荧光激光雷达测量六种典型生物战剂模拟物二维荧光光谱

对成团泛菌(Pan)、金黄色葡萄球菌金黄亚种(Sta)、球芽孢杆菌(BG)和大肠杆菌(EH)四种生物战剂模拟物进行了培养和生长曲线测定,四种菌的代时分别为0.99, 0.835, 1.07和1.909 h;设计研制了近场小型荧光测量激光雷达, 266和355 nm波长分别用于测量生物战剂模拟物氨基酸段和NADH段二维荧光谱;在可控的荧光测量腔室,测得了分辨率为4 nm的营养态细菌液态气溶胶以及牛血清(BSA)、卵清蛋白(OVA)两种毒素类模拟物液态气溶胶的二维荧光谱;二维荧光谱数据表明, Pan, Sta, BG, EH, BSA和OVA气溶胶,在氨基酸段的荧光谱形与标准荧光组分色氨酸较为一致, FWHM为60 nm,受培养生化环境、细菌内部荧光组分及比例的影响,荧光分子激发态与基态间的能量差增大,荧光谱带均存在不同程度的蓝/紫移;在Pan, Sta, BG和EH营养细菌气溶胶中均检出了较弱的NADH荧光组分,且水、氮等的拉曼散射不能完全扣除,光谱锯齿严重, FWHM为100 nm;二阶求导后的二维荧光谱表明,荧光谱的高阶处理和分辨识别是可行的。

激光光谱学

O433.54 2003053311CO2分子的近红外二极管激光吸收光谱灵敏探测=Sensitivedetection of CO2 molecule using near infrared diode laserabsorption spectroscopy[刊,中]/高晓明（中科院安徽光机所环境光谱学实验室.安徽,合肥（230031））,黄伟…//光学学报.-2003,23（5）.-609-611利用近红外二极管激光波长调制技术与二次谐波探测结合初步观测了CO2分子在波长1.57μm附近的吸收,获得了最小可探测吸收为8.6×10-5（信噪比为2）,对应500×10-6m-1的探测灵敏度。图4参7（于晓光）

基于统计中心线的目标特征提取算法研究

为了有效识别激光近场探测环境下的目标和云,提出了一种新的易于FPGA实现的目标特征提取算法。该算法提取了目标图像的突变、多分支、大角度、宽度变化等特征。测试结果显示,该算法能对目标进行有效识别。

Fabrication of Windowed Very-Small-Aperture Laser Diodes

A windowed very small aperture laser (VSAL) source for use in high resolution near field optical data storage is fabricated.The windowed regions are introduced to avoid shorting the pn junction with metal coating and suppress the COD effect.It facilitates producing VSAL by simplified technology and improves the laser performance.A VSAL with 400nm small aperture is demonstrated by focused ion beam (FIB) and the output power is 0 3mW at 31mA.

Near-Field Scattering Enhancement of Perylene Based Aggregates for Random Lasing

Strong near-field scattering enhancement (NFSE) of polyhedral oligomeric silsesquioxanes(POSS) nanoparticles (NPs) aggregates is found through physical simulation. An aggregation of N,N′-di-[3-(isobutyl polyhedral oligomeric silsesquioxanes) propyl] perylene diimide(DPP) which possesses POSS as scatteres experimentally performs strong NFSE, which confirms the physical simulation results. Moreover, coherent random laser is triggered from the DPP aggregates in carbon disulfide. It is the NFSE of POSS NPs connected to both ends of DPP through covalent bonds and the NFSE of their aggregation thanks to DPP’s aggregation that is responsible for the coherent random laser. So, this work develops a method to improve weak scattering of system through construction of molecules, and opens a road to a variety of novel interdisciplinary investigations, involving molecular designing for disordered photonics.

Electron-Positron Pair Production in an Arbitrary Polarized Ultrastrong Laser Field

Electron-positron pair production in an arbitrary polarized ultrastrong laser field is investigated in the first order perturbation approximation in which the Volkov states are used for convenient calculation of scattering amplitude and cross section. It is found surprisingly that the optimal pair production depends strongly on the polarization. For some cases of field parameters, the optimal field is e11iptically polarized or evenly circularly polarized one, rather than the usual linear polarization as indicated by previous works interesting unexpected features are a/so discussed briefly. Some insights into pair generation are given and some

Optical near-field excitation using liquid crystals on nanostruc- tured photoreactive molecular thin films

Optical near-field excitations were investigated on the basis of molecular alignment control of liquid crystals (LCs) on an optically rewritable nanostructure of photoreactive molecular thin films. Twisted nematic (TN) cells of LC molecules were constructed utilizing ITO substrates with 260 nm gratings of an azobenzene molecular thin film, fabricated using standing evanescent waves. The polarization changes of light transmitted through the TN cells, which were due to the alignment changes of LC molecules locally rubbed by the azobenzene nanogratings, were observed. Furthermore, we demonstrated local plasmon excitation of Au nanowires deposited on the azobenzene nanogratings using oblique vacuum evaporation, a phenomenon that produced strong anti-optical absorption spectra. The modulation of the local plasmon resonance in metallic nanowires decorated with LC molecules was confirmed.

Laser wavelength effects on(Ti,Al,Si)N in near-field laser nanostructuring by micron optical fiber enhanced irradiation

The effects of laser wavelengths(1064,532,355 and 266 nm)on nano-processing of fabricating a groove structure on(Ti,Al,Si)N alloy film using the micro-fiber near-field enhanced irradiation are investigated.It is observed that variations of laser wavelength can effectively change the widths of the groove structures,which are featured as one-dimension bowl-like structures.The minimum of the groove width can be achieved at 293 nm with a 532 nm laser inducing.In order to fabricate the groove in nanoscale,enough energy is delivered onto(Ti,Al,Si)N surface by a single laser pulse.Simulation results are also discussed to understand the experimental results.