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We propose a method of reconstructing an image from a volume hologram at a wavelength different from the recording one. Spectrally broad but spatially coherent light was used as a probe beam. Each angular spectral component of the recorded hologram could be Bragg matched at one particular wavelength within the broadband spectrum. We experimentally demonstrated that a whole image could be reconstructed by using polychromatic light, whereas only a partial image was obtained by using single-mode laser light. We discuss the required bandwidth of the probe beam and the deformation of the reconstructed image. 相似文献
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双折射双频激光器输出光偏振特性的实验研究 总被引:7,自引:2,他引:5
报道了双折射双频激光器输出光偏振特性的实验研究,实验发现双折射双频激光器两端输出的线偏振光的偏振方向并不一致,而相互有一定的旋转角度,实验也再次证明了激光器输出的是正交线偏振光,而不是晶体本征模的椭圆化了的偏振光。 相似文献
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除了激光源、偏振分光镜(PBS)和波片等偏振器件之外,非偏振分光镜(NPBS)也是外差干涉仪中重要的非线性误差源。研究了多层介质膜NPBS的退偏效应和方位角对非线性误差的影响。采用p、s分量透射比、反射比、反射相移和透射相移共同表征NPBS的退偏效应,并逐项分析了其非线性误差模型。如果入射光束为理想线偏振光,则只有NPBS的反射相移和透射相移影响测量精度。如果入射光束存在偏振椭圆化和非正交,则NPBS的方位角、透射比和反射比、相移等参数的变化都会引入非线性误差,误差曲线的斜率受椭圆率和非正交角的影响。因此选用不同的激光源,同一个NPBS产生的非线性误差大小不同,一般可达几个纳米量级。为了实现纳米/亚纳米级精度的外差干涉测量,选择性能稳定的NPBS,特别是NPBS退偏效应与激光源输出偏振态之间的匹配非常重要。 相似文献
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The digital holographic technique is applied to analyze the spatial distribution of polarization state of light transmitted
through anisotropic objects using an orthogonal linearly polarized reference beam. The polarization orientation of reference
beam is switched by an optical fiber Faraday rotator for successive hologram recording. To confirm the principle of polarization
analysis, a quarter wave plate (QWP) is used and the distribution of polarization state over the object surface is analyzed
for various orientations of the QWP. By providing an area of a known polarization for a part of the object wave as a reference,
a phase drift of the reference waves can be evaluated and compensated for using the reference area. The principal axis and
ellipticity of polarization ellipse are calculated and compared with their theoretical values. A good agreement between the
experimental and theoretical values is observed. 相似文献
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本文提出一种可以分别再现双脉冲曝光粒子场全息图的两幅图像的技术,记录全息图时,利用电光晶体和偏振分光棱镜,使两个光脉冲的物光波或参考光波沿不同的空间路径到达全息底板,从而通过不同的空间滤波在再现全息图时分别获得对应于不同脉冲时刻的粒子场图像.实验证实了该技术的可行性. 相似文献
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Smolovich AM Alvarez E Aseyev SA Cervantes MA Chekalin SV Serov OB Terpugov VS 《Optics letters》2008,33(20):2401-2403
Holograms were recorded by 30 fs laser pulses in 20 microm film of dichromated gelatin on the polished quartz substrate and reconstructed in the waveguide mode. The geometric-optical regime of waveguide hologram reconstruction was obtained: the direction of the reconstructed beam was observed to be independent on the reconstructing wavelength within the hologram spectral selectivity band. We discuss the possibility of producing achromatic waveguide optical elements containing only a few periods. 相似文献
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An experimental study on the polarization dependence of the quadratic photocurrent in commercial light emitting diodes (LEDs)
has been carried out using 200 fs laser pulses from a cw mode-locked Nd:glass oscillator. The variation of induced quadratic
current with respect to orientation of polarization of the laser beam is measured using single and double beams. Cross-polarized
autocorrelation measurements have been performed in real time at different orientations of the LEDs to differentiate the contributions
to the quadratic photocurrent of two-photon absorption and second harmonic generation. The theoretical analysis of cross-polarized
signals under different orientations is presented.
PACS 42.65.Re; 42.65.ky; 42.50.Hz; 85.60.Jb 相似文献
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When a laser source is used to illuminate a transmission hologram, the zero order beam is not utilised and is just wasted. The paper describes a new technique for economical utilisation of laser light by recycling the transmitted light to reconstruct a number of holograms simultaneously for viewing by a large number of observers. There is no danger to viewer who is exposed to the undiffracted laser beams transmitted through the hologram. The paper also discusses the diffraction efficiency requirement of successive hologram and the limit of number of holograms in the scheme. 相似文献
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A liquid crystal polarization rotator (LCPR) to reduce the intermodulation spatial-bandwidth in offset-reference holography is proposed. The LCPR is divided into two portions which rotate the direction of polarization of the incident light beam differently. The rotation angle is set so that the direction of polarization of the transmitted light beams make an angle 90° with each other, so that object beams through the two portions do not interfere with each other. This rotator reduces the spatial frequency range of hologram intermodulation noise to 1/2 that of the conventional hologram recording method. 相似文献
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J.I.B. Wilson 《Contemporary Physics》2013,54(2):153-155
Holography is a two-stage process of photography using coherent light from a laser to illuminate the scene. In the first stage a hologram is formed by combining the light scattered from the object and the direct laser beam on a photographic plate. In the second stage a three-dimensional image is reconstructed without the use of lenses, by directing the laser beam through the hologram. Applications of holography include information storage, recording of images in depth, the use of holograms as optical elements, and as a means of performing precise interferometric measurements on three-dimensional objects of any shape and surface finish. 相似文献
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The improved method for calculation of a phase hologram and its application to laser writing of waveguides with a spatial light modulator are presented. It was found that the amplitude and phase distributions of light spots generated by a phase hologram can be distorted compared to those of a focused single beam. The distortion of light spots could be reduced by adding a simple constraint, in which light intensities around a light spot should be as small as possible, to the conventional calculation method of a phase hologram. It was also demonstrated that the improved calculation method can be considered essential for laser writing of waveguides. 相似文献
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Changjun Min Jinpeng Liu Ting Lei Guangyuan Si Zhenwei Xie Jiao Lin Luping Du Xiaocong Yuan 《Laser \u0026amp; Photonics Reviews》2016,10(6):978-985
Traditional detour‐phase hologram is a powerful optical device for manipulating phase and amplitude of light, but it is usually not sensitive to the polarization of light. By introducing the light‐metasurface interaction mechanism to the traditional detour phase hologram, we design a novel plasmonic nano‐slits assisted polarization selective detour phase meta‐hologram, which has attractive advantages of polarization multiplexing ability, broadband response, and ultra‐compact size. The meta‐hologram relies on the dislocations of plasmonic slits to achieve arbitrary phase distributions, showing strong polarization selectivity to incident light due to the plasmonic response of deep‐subwavelength slits. To verify its polarization sensitive and broadband responses, we experimentally demonstrate two holographic patterns of an optical vortex and an Airy beam at p‐ and s‐polarized light with wavelengths of 532nm, 633nm and 780nm, respectively. Furthermore, we realize an application example of the meta‐hologram as a polarization multiplexed photonic device for multi‐channel optical angular momentum (OAM) generation and detection. Such meta‐holograms could find widespread applications in photonics, such as chip‐level beam shaping and high‐capacity OAM communication.
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本文报道了一项称为载波相移全息干涉计量的自动相位估算的新技术。该技术的主要特点是不同相移的条纹图案可用双曝光全息重视。这样即可用来对与时间相关的问题进行自动相位估算。 相似文献
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Ping Yang Manfred Wendisch George Kattawar Yongxiang Hu 《Journal of Quantitative Spectroscopy & Radiative Transfer》2011,112(12):2035-2039
This note reports on the effects of the polarization state of an incident quasi-monochromatic parallel beam of radiation and the orientation of a hexagonal ice particle with respect to the incident direction on the extinction process. When the incident beam is aligned with the six-fold rotational symmetry axis, the extinction is independent of the polarization state of the incident light. For other orientations, the extinction cross-section for linearly polarized light can be either larger or smaller than its counterpart for an unpolarized incident beam. Therefore, the attenuation of a quasi-monochromatic radiation beam by an ice cloud depends on the polarization state of the beam if ice crystals within the cloud are not randomly oriented. Furthermore, a case study of the extinction of light by a quartz particle is also presented to illustrate the dependence of the extinction cross-section on the polarization state of the incident light. 相似文献
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可见光再现X射线无透镜傅里叶变换全息图的可行性研究 总被引:1,自引:1,他引:0
本文探讨了可见光再现X射线无透镜傅里叶变换全息图的可行性问题,结论是,可见光再现X射线无透镜傅里叶变换全息图,可以做到不但没有球差,而且在一定条件下慧差也可完全消除,其余像差也可校正最小,以臻忽略不计。 相似文献
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Generation of arbitrary vector beams with a spatial light modulator and a common path interferometric arrangement 总被引:3,自引:0,他引:3
We describe a convenient approach for generating arbitrary vector beams in a 4-f system with a spatial light modulator (SLM) and a common path interferometric arrangement. A computer-generated hologram is introduced onto SLM for performing the beam conversion. Optical realization of a variety of polarization configurations confirms the reliability and flexibility of our method. 相似文献
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提出外腔延时反馈半导体激光器混沌偏振可调控制方法,分别建立了垂直正交偏振延时双反馈、同偏振面方向延时双反馈以及任意可调偏振延时双反馈激光动力学物理模型. 通过调节激光器外腔光路中的平面镜和光衰减器可控制一平面偏振反馈光的延时时间及光反馈量,或调节一偏振反馈光的偏振面到另一个偏振反馈光的偏振面方向上或者到任意偏振方向都可进行激光混沌控制. 数值结果证明该方法可以控制激光混沌到单周期态、多周期态等,还发现该控制可使激光器同时呈现偏振周期振荡、偏振反周期振荡、稳定三种动力学行为等.
关键词:
混沌
控制
激光器
偏振 相似文献
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G. Baum C. D. Caldwell W. Schröder 《Applied Physics A: Materials Science & Processing》1980,21(2):121-126
A lithium-6 atomic beam is spin-polarized by means of optical pumping with a single-mode dye laser operating on the resonance
transition. Simultaneous pumping of both hyperfine substates is achieved by frequency-splitting the laser light with an acousto-optic
modulator. A polarization dependent signal, obtained by probing the optical activity of the beam with linearly polarized light,
is utilized in a microprocessor-controlled laser stabilization scheme. The polarization is analyzed with a sextupole magnet
and its overall value is 0.70 for an intensity of 1×1014 atms s−1. By reversing the sense of circular polarization of the pumping light the atomic beam polarization is easily reversed in
direction. 相似文献