共查询到20条相似文献,搜索用时 0 毫秒
1.
A novel Zeeman laser-scanning confocal microscope (ZLSCM) is proposed. It has the same configuration as the conventional laser-scanning confocal microscope (LSCM) in which a Zeeman laser in conjunction with a Glan-Thompson analyzer is used. In our system, the analyzer with the bandpass filter, which act simultaneously as a polarization gate and a coherence gate, enhance the collection efficiency of the weak-scattering photons and simultaneously suppress the multiple-scattering photons. The improvement in depth resolution of a ZLSCM in a scattering medium compared with that of a conventional LSCM is discussed and demonstrated experimentally. 相似文献
2.
A simple and accurate algorithm (phase scanning method) is proposed for 3D surface contouring and dynamic response determination of a vibrating object. A sinusoidal fringe pattern is projected onto a low-frequency vibrating object by a programmable liquid crystal display projector. The fringe patterns are captured by a high-speed CCD camera with a telecentric gauging lens. Phase values are evaluated point by point using phase scanning method. From the phase values of each point on the object, the contour of the specimen at different instants of vibration can be retrieved. In this paper, a small vibrating coin is used to demonstrate the validity of the method and the experimental results are compared with test results on a stationary coin using four-step phase shifting and fast Fourier transform methods. The technique is especially useful in applications where the vibrating object has a complicated shape. 相似文献
3.
研究了大口径非球面光学元件表面轮廓测量过程可视化,并设计、开发了基于双向链接边表的软件系统。提出一种改进的双向链接边表数据结构完成三维模型加载方法,建立数据结构及其相关图形元作为软件的基础层。计算非球面曲面方程获得表面轮廓的数据生成图形场景节点,并自动生成曲面测量轨迹。在非接触检测平台上进行测试,对测量数据进行平滑处理,拟合出测量获得的非球面面形,完成面形精度和表面粗糙度的评价。实验结果表明,该可视化系统技术路线正确高效、稳定性好,为非球面检测数据及其综合分析仿真提供直观的可视化平台。 相似文献
4.
研究了大口径非球面光学元件表面轮廓测量过程可视化,并设计、开发了基于双向链接边表的软件系统。提出一种改进的双向链接边表数据结构完成三维模型加载方法,建立数据结构及其相关图形元作为软件的基础层。计算非球面曲面方程获得表面轮廓的数据生成图形场景节点,并自动生成曲面测量轨迹。在非接触检测平台上进行测试,对测量数据进行平滑处理,拟合出测量获得的非球面面形,完成面形精度和表面粗糙度的评价。实验结果表明,该可视化系统技术路线正确高效、稳定性好,为非球面检测数据及其综合分析仿真提供直观的可视化平台。 相似文献
5.
《中国光学快报(英文版)》2015,(10)
We present a Fizeau interferometer using a microscopic objective as a tool for surface contouring without the need for a numerical lens for reconstruction. The interferometer is associated with a telescope system to feature the object with collimated light. The experiment is conducted on two objects possessing different step heights.The phase maps from the captured off-axis holograms are calculated numerically, which allows us to deduce the contours of the objects. The great advantages of the presented technique are that it can be done in real time and there is no need for numerical lenses for micro-objects reconstruction. 相似文献
6.
K. Kobayashi H. Yamada K. Umeda T. Horiuchi S. Watanabe T. Fujii S. Hotta K. Matsushige 《Applied Physics A: Materials Science & Processing》2001,72(7):S97-S100
We measured surface potential (SP) on a ?-conju-gated thiophene oligomer monolayer film deposited on a metallic substrate by Kelvin probe force microscopy using a piezoelectric cantilever. Since the cantilever has a relatively large spring constant (calculated as about 150 N/m), the frequency modulation detection method was used for tip-sample distance regulation in order to achieve high-sensitivity SP measurement. A contact potential difference between monolayer regions and the metallic substrate was clearly observed in an SP image. Furthermore, an apparent change in a contrast of the SP image was observed while the sample was irradiated with ultraviolet light. 相似文献
7.
J.J. Kolodziej B. Such M. Goryl F. Krok P. Piatkowski M. Szymonski 《Applied Surface Science》2006,252(21):7614-7623
Surfaces of several AIIIBV compound semiconductors (InSb, GaAs, InP, InAs) of the (0 0 1) orientation have been studied with noncontact atomic force microscopy (NC-AFM). Obtained atomically resolved patterns have been compared with structural models available in the literature. It is shown that NC-AFM is an efficient tool for imaging complex surface structures in real space. It is also demonstrated that the recent structural models of III-V compound surfaces provide a sound base for interpretation of majority of features present in recorded patterns. However, there are also many new findings revealed by the NC-AFM method that is still new experimental technique in the context of surface structure determination. 相似文献
8.
P. J. Chandley 《Optical and Quantum Electronics》1979,11(5):407-412
When a rough surface is viewed in an interference microscope with tilt fringes introduced, the effect of the roughness is to reduce the average visibility of the tilt fringes. The relationship between the standard deviation of surface height and the average visibility of the tilt fringes is derived, and experimental results are presented of measurements made on ground glass surfaces using a Linnik interference microscope. 相似文献
9.
10.
Surface measurement using active vision and light scattering 总被引:3,自引:0,他引:3
This paper reviews the recent progress in surface measurement methods using active vision and light-scattering techniques. The active vision methods with different structured light patterns and the corresponding techniques are summarized. The surface roughness and defects inspection with light-scattering are discussed. After the review, an integrative method to measure surface waviness and form, roughness is proposed. 相似文献
11.
12.
This paper presents a digital projection grating method for full field measurement of out-of-plane deformation and shape of an object. Two grating patterns on an object before and after deformation are captured by a CCD camera and stored in a computer. With the aid of Fast Fourier Transform (FFT) and signal demodulating techniques, a wrapped phase map is generated. The phases are expanded in the range of 0–2π and compared with the resulting moiré pattern. An unwrapping procedure is used to obtain a continuous phase. In addition, a digital method for fractional fringe multiplication is also developed. Results on deformation and object profile measurements are presented. 相似文献
13.
Young-Min Hwang Sung-Won Yoon Jung-Hwan Kim Souk Kim Heui-Jae Pahk 《Optics and Lasers in Engineering》2008,46(2):179-184
We proposed a new method for retrieving the phase from wavelength-scanning interferogram by wavelet transform. We demonstrate, with both theoretical and experimental data, that this method provides a reliable technique for retrieving phase in the wavelength-scanning interferometry. We show that the proposed method by wavelet transform can reconstruct the nonlinear phase better than the conventional Fourier transform and direct spectral phase calculation method by simulation. The patterned thin film is measured to get the thickness and surface profile simultaneously with the developed wavelength-scanning interferometry. 相似文献
14.
《Applied Surface Science》1987,28(1):53-62
Fast atom bombardment mass spectroscopy (FAB-MS) is used to perform depth profile measurement of an artificial PMMA-PTFE thin film sandwich. It is shown that either the total ion current change or characteristic polymer fragment intensity changes (with respect to time) can be used to locate and study the polymer-polymer interface. Primary and secondary particle beam effects (crater-edge effects, radiation damage accumulation and surface morphology development) are documented and the potential for more advanced FAB-MS polymer-polymer interface studies based on further optimization of experimental conditions is discussed. 相似文献
15.
We present low energy electron microscope (LEEM) spectromicroscopy studies of surface plasmons, localized on micro- and nanoscale epitaxial Ag islands. Excellent agreement is found in a direct comparison of wave vector dependent plasmon intensity with theory, demonstrating that high quality quantitative data can be obtained with a large improvement in both spatial and temporal resolution over traditional electron scattering experiments. The plasmon signal from Ag islands is successfully imaged with a spatial resolution of less than 35 nm. LEEM based plasmon spectromicroscopy promises to be a powerful tool for furthering our understanding of nanoplasmonics. 相似文献
16.
Jonathan Hobley Tomoya Oori Shinji Kajimoto Sergey Gorelik Dirk Hönig Koji Hatanaka Hiroshi Fukumura 《Applied Physics A: Materials Science & Processing》2008,93(4):947-954
A technique is described to observe transient events in thin interfacial films and monolayers. p-polarized light has minimum
reflectivity at the Brewster angle. When an interface is viewed with light that is both incident and reflected at the Brewster
angle the resulting image is dark. However, small refractive index changes can increase the reflectivity producing a high-contrast
image of an altered interface with a dark background level. Using this phenomenon, with imaging optics, photo-induced phase
change in Langmuir films was monitored. Two synchronized 5-ns pulsed lasers were used in the pump–probe configuration to induce
changes at an air–liquid interface and to monitor the resulting morphology changes at selected time delays after photo-excitation.
The photo-responsive layers were made from photochromic spiropyrans, having long aliphatic chain substituents. When irradiated
with UV light the closed form of the molecule converts to a more planar ring open merocyanine form. This results in the layers
changing their morphology in order to accommodate the new molecular form. 相似文献
17.
This study proposes an image processing method to improve the quality of interference fringes in mode-shape measurement using temporal speckle pattern interferometry. A vibrating piezoelectric plate at resonance was investigated, and the full-field optical information was saved as a sequence of images. According to derived statistical properties, an algorithm was developed to remove noise from both the background and disturbance, resulting in high-resolution images of excellent quality. In addition, the resonant frequency and mode shape obtained using the proposed algorithm demonstrate excellent agreement with theoretical results obtained by the finite element method. 相似文献
18.
A method of thickness measurement of cobalt foils using transverse ultramicrotome cuts of foils embedded in Araldite is described. A new two-stage gelatine-carbon replica technique was developed. For a foil with inhornogeneous thickness, the method enables an exact determination of the position on the foil of the spot where thickness is measured. Although glass knives only were available for cutting, the accuracy of thickness measurement was better than ±1000 Å. 相似文献
19.
Conventional methods determine the ultrasonic wave speed by measuring the medium path length propagated by a pulsed wave and the corresponding time-of-flight. In this study, the wave speed is determined without the need of the path length. A transmitting transducer sends a pulsed wave into the medium (constant wave speed along the beam axis) and the backscattered signal is collected by a hydrophone placed at two distinct positions near the transmitted beam. The time-delay profile, between gated windows of the two rf-signals received by the hydrophone, is determined using a cross-correlation method. Also, a theoretical time-delay profile is determined considering the wave speed as a parameter. The measured wave speed is obtained upon minimization of the RMS error between theoretical and experimental time-delay profiles. A PZT conically focused transmitting transducer with center frequency of 3.3 MHz, focal depth of 20 mm and beam width (-6 dB) of 2 mm at the focus was used together with a PZT hydrophone, 0.8 mm in aperture. The method was applied to three phantoms (wave speed of 1220, 1501 and 1715 m/s) and, in vitro, to fresh bovine liver sample, immersed in a temperature-controlled water bath. The results vary within 3% of those obtained with a conventional method. 相似文献
20.
White-light interferometric techniques have been widely used in three-dimensional (3D) profiling. This paper presents a new method based on vertical scanning interferometry (VSI) for the 3D profile measurement of a micro-component that contains sharp steps. The use of a white-light source in the system overcomes the phase ambiguity problem often encountered in monochromatic interferometry and also reduces speckle noises. A new algorithm based on the continuous wavelet transform (CWT) is used to retrieve the phase of an interferogram. The algorithm accurately determines local fringe peak and improves the vertical resolution of the measurement. The proposed method is highly resistant to noise and is able to achieve high accuracy. A micro-component (lamellar grating) fabricated by sacrificial etching technique is used as a test specimen to verify the proposed method. The measurement uncertainty of the experimental results is discussed. 相似文献