消像差条件在共形光学系统中的应用

根据轴对称光学系统中的消像散条件探讨了共形整流罩结构中消像散万向节点位置的存在性.在此基础上,对共形光学系统中消像差万向节点位置进行了理论推导.软件分析结果表明,轴对称光学系统消像差条件对于共形光学系统的设计仍有良好的指导意义,由此得到的"消像差"共形光学系统的残余像差已处于实际成像系统的像差校正能力范围之内.     

The proteome of lentil (Lens culinaris Medik.) seeds: Discriminating between landraces

Lentil (Lens culinaris Medik.) is one of the most ancient crops of the Mediterranean region used for human nutrition; an extensive differentiation of L. culinaris over millennia has resulted in a number of different landraces. As a consequence of environmental and socio‐economic issues, the disappearance of many of them occurred in more recent times. To investigate the potential of proteomics as a tool in phylogenetic studies, testing the possibility to identify specific markers of different plant landraces, 2‐D gel electrophoretic maps of mature seeds were obtained from seven lentil populations belonging to a local ecotype (Capracotta) and five commercial varieties (Turca Rossa, Canadese, Castelluccio di Norcia, Rascino and Colfiorito). 2‐DE analysis resolved hundreds of protein species in each lentil sample, among which only 122 were further identified by MALDI‐TOF PMF and/or nanoLC‐ESI‐LIT‐MS/MS, probably as a result of the poor information available on L. culinaris genome. A comparison of these maps revealed that 103 protein spots were differentially expressed within and between populations. The multivariate statistical analyses carried out on these variably expressed spots showed that 24 protein species were essential for population discrimination, thus determining their proposition as landrace markers. Besides providing the first reference map of mature lentil seeds, our data confirm previous studies based on morphological/genetic observations and further support the valuable use of proteomic techniques as phylogenetic tool in plant studies.     

Interferometric specification of lens (single and doublet) parameters

Three-dimensional analysis of intensity distribution in the interference field of two interfering waves enables one to reconstruct the corresponding wave vectors at each point in space. This has been exploited to specify the radii of curvature, the refractive indices and the thicknesses of a single lens and components of a doublet. The introduced technique is very suitable for lenses of small diameters and short focal lengths.     

Thermal considerations on the design and operation of lens ducts

In this paper, heat effects due to powerful pump beam in the lens duct delivery system is investigated and subsequent thermal effects are described. Temperature raise in the device, thermal loading, and material considerations for the lens ducts fabrication are reported. For an absorbed intensity of 10 W/cm² in a 4 cm-long lens duct, the temperature difference between the midpoint and its faces, for a lens duct made from borosilicate is 7.05°C, for sapphire 4.01°C, and for synthetic fused silica is the smallest value of 0.54°C. For a typical absorbed intensity of 1.4 W/cm² in a 4 cm-long lens duct, with a steady-state time constant of 120 s, the fractional thermal loading is 1.98% for BK-7, 1.89% for sapphire, and only 0.16% for synthetic fused silica. By considering different glass materials, the overall results show that synthetic fused silica is superior to some other materials for the fabrication of a lens duct. The reported analytical method and the results of parametric studies can be helpful in material selection and construction of an effective lens duct.     

非球面聚焦透镜数控加工技术研究

 国内现有的高功率固体激光装置所使用的非球面聚焦透镜都是用传统方式手工加工而成的，由于手工加工方式的加工精度和进度对人的依赖性很大，势必影响大批量制造时的工程进度。而采用新兴的小磨头数控加工技术则可以避免这些缺点。介绍了首次将小磨头数控加工技术用于非球面聚焦透镜的加工，对其中各项技术，包括典型靶镜参数、机床控制方式、加工运动方式、实验使用参数、检测方式进行了分析，并得到了预期的实验结果。     

自聚焦排透镜参数分析及制作

自聚焦排透镜(SLR)是利用自聚焦透镜(SELFOC LENS)制作的一成象器件。本文就SLR的工作原理,及各参数对成象的影响进行了分析。并实际制作了几种不同规格的自聚焦排透镜为研制自聚焦排透镜提供了极好的基础。     

Very low optical absorptions and analyte concentrations in water measured by Optimized Thermal Lens Spectrometry

Thermal Lens Spectrometry has traditionally been carried out in the single-beam and the mode-mismatched dual-beam configurations. Recently, a much more sensitive dual-beam TL setup was developed, where the probe beam is expanded and collimated. This feature optimizes Thermal Lens (TL) signal and allows the use of thicker samples, further improving the sensitivity. In this paper, we have made comparisons between the conventional and optimized TL configurations, and presented applications such as measurements of very low absorptions and concentrations in water and Cr(III) aqueous solution in the UV-vis range. For pure water we found linear absorption coefficients as low as the Raman scattering one due to the stretching vibrational modes of OH group. The detection limit was estimated 1 × 10⁻⁶ cm⁻¹ with a 180-mW excitation power using a 100-mm cell length. This sensitivity is very high, considering that water has a photothermal enhancement factor ∼33 times smaller than CCl₄, for example. For Cr(III) species in aqueous solution, the limit of detection (LOD) was estimated in ∼40 ng mL⁻¹ at 514 nm, or ∼10 ng mL⁻¹ at 405 nm, which is ∼30 times smaller than the LOD achieved with conventional transmission techniques. The more recent TL configuration is very attractive to obtain absorption spectra, since the result does not depend critically on the beam parameters, unlike the other configurations. The main drawbacks of this optimized TL configuration are the longer acquisition time and the need for larger samples.     

Using the camera pin-hole model restrictions to calibrate the lens distortion model

Camera calibration required the computation of camera pin-hole and lens distortion models. The lens distortion is estimated alone or together with the pin-hole model, by using some existing lens distortion non-metric or self-calibration methods. If both models are computed together, then the models are adjusted to training data, but not to real camera. This is because both pin-hole and lens distortion models are coupled. If they are computed separately, difficulties arise since calibration of lens distortion alone is an unstable process. To improve existing camera calibration methods, this paper proposes a metric calibration method to compute lens distortion separately from the pin-hole model. This method is solved under stable conditions, independently of the computed lens distortion model, since pin-hole and distortion models are computed separately. Images of a planar template are used. First, using distorted control points extracted from images, a set of undistorted points which fits in the pin-hole model are computed. Second, with distorted and undistorted control points, lens distortion is calibrated by using a metric calibration process.     

Extending the depth of focus with high NA lens axicon

Based on vectorial Debye theory, tight focusing of x-polarized beam with high NA lens axicon is studied. The high NA lens axicon utilizes spherical aberration to duplicate the performance of an axicon and to create an extended focal line. The intensity distribution in the focal region is illustrated by numerical calculations. We show that the high NA lens axicon system can generates a sub wavelength beam (0.826λ) with depth of focus around 10λ.     

高动态范围激光等离子体诊断系统及其在惯性约束聚变实验中的应用

基于高功率激光等离子体X射线辐射谱特性,设计和研制了一种大画幅高动态范围MCP选通型分幅相机. 单画幅宽度13mm,长度36mm,曝光时间0.5—5ns可调.与X射线CCD比较,系统在1.0—10keV的谱响应相对平整,无高能增强效应.利用高功率激光打靶实验进行了性能考核实验,结果表明,系统的信噪比明显好于X射线CCD系统,动态范围大于3×10³. 系统已经在神光Ⅱ装置ICF物理实验中获得成功应用. 关键词： 动态范围 谱响应 激光等离子体诊断 分幅相机