共查询到20条相似文献,搜索用时 171 毫秒
1.
分光器件是全息光栅曝光系统中的关键光学元件,它将入射激光光束分成两束,两相干光束叠加后形成干涉条纹。曝光系统的稳定性不但影响干涉条纹对比度,还影响光栅衍射波前像差、杂散光水平以及光栅掩模刻槽质量。为了提高曝光系统的稳定性,分析入射光束角度偏离与两相干光束夹角(2θ)的关系,并结合干涉条纹周期公式,分别导出了以光栅和棱镜作为分光器件时入射激光束角度偏离量与待制作光栅空间相位差的解析表达式,据此分析了光栅和棱镜曝光系统的稳定性。结果表明,采用光栅分光的曝光系统的稳定性比棱镜分光曝光系统稳定性提高5~6个数量级,这对长时间曝光制作全息光栅具有实际意义。 相似文献
2.
The fourier-transform patterns of an object are usually observed in the far-field region or obtained in the near-field region with the help of lenses. Here we propose and experimentally demonstrate a scheme of Fourier-transform patterns in the Fresnel diffraction region with thermal light. In this scheme, neither a lens nor a beamsplitter is used, and only one single charge coupled device(CCD) is employed. It means that dividing one beam out of a light source into signal and reference beams is not as necessary as the one done by the use of a beamsplitter in usual ghost interference experiments.Moreover, the coincidence measurement of two point detectors is not necessary and data recorded on a single CCD are sufficient for reconstructing the ghost diffraction patterns. The feature of the scheme promises a great potential application in the fields of X-ray and neutron diffraction imaging processes. 相似文献
3.
Jun-hua Chen Hong-yi Fan Xu-bing Tang 《International Journal of Theoretical Physics》2012,51(1):14-22
It is known that beamsplitter can be used to produce quantum entanglement, in this paper we examine this topic from the point
of view of Wigner operators. Using Weyl-ordering of the Wigner operator and the Weyl ordering invariance of Weyl ordered operators
under similarity transformation we derive the entanglement rule of Wigner operators at a beamsplitter. 相似文献
4.
We propose a new implementation of a quantum speed meter QND measurement scheme. It employs two independent optical readouts of the interferometer test masses with different values of the bandwidths and of the optical circulating power, whose outputs have to be combined by an additional beamsplitter. Signals at the two outputs of the beamsplitter are proportional to the position and the velocity of the test masses, respectively. The influence of the position meter-like back action force associated with the position signal can be cancelled using the EPR approach by measuring the amplitude quadrature of the beamsplitter common output. 相似文献
5.
6.
G. F. Brand 《International Journal of Infrared and Millimeter Waves》2002,23(9):1271-1285
A conducting strip grating can be designed to serve as a beamsplitter that, when a monochromatic linearly-polarized plane wave is incident upon it, delivers circularly-polarized transmitted and reflected waves. The theoretical result is confirmed by a microwave experiment at 35 GHz. 相似文献
7.
J.A. MacAndrew 《Optics Communications》1979,29(2):141-146
It is shown that for a linear holographic recording material in which a dc intensity level in fringes of contrast less than unity does not affect the maximum attainable diffraction efficiency, the minimum exposure time is obtained when the available power is divided equally into reference and object beams at the beamsplitter. Certain photoresists when appropriately processed approach this ideal. It is shown that for particular photoresists (Shipley AZ-1300 series), nonlinearities cause the optimum power ratio at the beamsplitter to be other than 1 : 1, and it is shown how the optimum power ratio may be determined. 相似文献
8.
仅仅使用一个单独的分光棱镜(BS),实现了一种用于生物细胞三维成像的双通路定量相位显微术.不同于传统的使用方法,将BS倾斜放置,使中央半反射层与入射光光轴之间存在一个非常小的角度.这样基于BS的分光特性,经过BS后的透射光束和反射光束将会叠加在一起并形成干涉.调节样品位置,利用相机拍摄同时获得了存在π相移的双通路干涉图.这种离轴干涉模式,只需要记录单幅干涉图就可以获得真实的相位信息,方法结构简单,易于操作,适用于微小透明样品的三维形貌测量. 相似文献
9.
The textbook aproach to light amplification is based on the idea that photons act as independent particles. If atomic stimulation is instead attributed to the action of the Einstein-de Broglie wave, a different photon distribution is obtained. Coincidence experiments can easily observe the difference between the two approaches if an amplifier is set on one of the two beams emerging from a beamsplitter. 相似文献
10.
提出一种单光子探测器量子效率的绝对自身标定方案,利用光参量下转换过程中产生的光子对在时间上的相关性,先将参量光束分为两路,然后引入相对延时,使同时产生的孪生光子先后进入单光子探测器,然后将探测器之后的电路分为三路,其中一路直接进入计数器得到探测器所探测到的光子的总计数率,另两路用电路方法引入和光路相当的相对延时,经符合电路后进入计数器,得到前后到达探测器的光子对之间的符合计数率.这样,从符合计数率与总光子计数率之比即可在不需要任何其他探测器或者参照标准的情况下获得探测器的量子效率.文中给出两种方案,分别适 相似文献
11.
We introduce a new four-mode continuous-variable entangled state in Fock space which can compose a new quantum mechanical
representation. This state is important and can be common used because it can be generated by using one symmetrical beamsplitter
and a pair of parameter down-convertors. Applying this new state in quantum information is described. 相似文献
12.
M. Larqué A. Beveratos I. Robert-Philip 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,47(1):119-125
We report on a scheme for the creation of time-bin entangled states out of two subsequent single photons. Both photons arrive
on the same input port of a beamsplitter and the situation in which the photons leave the beamsplitter on different output
ports is post-selected. We derive a full quantum mechanical analysis of such time-bin entanglement for emitters subject to
uncorrelated dephasing processes and apply this model to sequential single photons emerging from a single semiconductor quantum
dot. Our results indicate that the visibility of entanglement is degraded by decoherence effects in the quantum dot, but can
be restored by use of CQED effects, namely the Purcell effect. 相似文献
13.
14.
We report on processing the spectral interference signals by a new method based on a windowed Fourier transform applied in the wavelength domain. First, the numerical simulations are performed to demonstrate high precision of the phase retrieval from the spectral signal. Second, the feasibility of the method is confirmed in processing experimental data from a dispersive Michelson interferometer comprising a cube beamsplitter made of BK7 glass. From the retrieved spectral phase difference, the effective thickness of the beamsplitter is determined precisely. 相似文献
15.
对双波段红外扫描成像光学系统进行了研究,结合三次成像技术和100%冷光栏效率技术,设计了一个共口径双通道红外扫描成像光学系统。该系统包括前端共用的双反射系统、分束镜、准直镜组、扫描镜和成像镜组。光波经过双反射系统在主镜之后被分束镜分成中波红外通道(3 m~5 m)和长波红外通道(10 m~12 m),经准直镜组及成像镜组会聚探测器上,实现中波红外系统与长波红外系统共口径同步成像。设计结果表明,长波红外系统传递函数在18 lp/mm处达到0.4以上,中波红外系统传递函数在18 lp/mm处达到0.78以上,满足实际应用的要求。 相似文献
16.
《中国物理 B》2021,30(5):50302-050302
17.
Differential correction system of laser beam directional dithering based on symmetrical beamsplitter
This paper proposes a differential correction system with a differential optical path and a symmetrical beamsplitter for correcting the directional dithering of the laser beams. This system can split a collimated laser beam into two laser beams with equal and opposite movements. Thus, the positional averages of the two split laser beams remain constant irrespective of the dithering angle. The symmetrical beamsplitter designed based on transfer matrix principle is to balance the optical paths and irradiances of the two laser beams. Experimental results show that the directional dithering is reduced to less than one-pixel value. Finally, two examples show that this system can be widely used in one-dimensional measurement. 相似文献
18.
An on-axis phase-shifting reflective point-diffraction microscopic interferometer for quantitative phase microscopy based on Michelson architecture is proposed.A cube beamsplitter splits the object wave spectrum into two copies within two arms.Reference wave is rebuilt in one arm by low-pass filtering on the object wave frequency spectrum with a pinhole-mask mirror,and interferes with the object wave from the other arm.Polarization phase-shifting is performed and phase imaging on microscale specimens is implemented.The experimental results demonstrate that the proposed scheme has the advantage of long-term stability due to its quasi common-path geometry with full use of laser energy. 相似文献
19.
The existence of decoherence-free subspace (DFS) has been discussed widely. In this paper, we propose an alternative scheme for generating the four-atom W states by manipulating DF qubits. The atoms are divided into two pairs and trapped in two separate optical cavities. Manipulation of atoms within DFS may generate a two-atom maximally entangled state in an individual cavity, which is a stable state. After driving the system out of DFS, the atoms will interact resonantly with the cavity field. The photons leaking from the cavities interfere at the beamsplitter, which destroys which-path information, and are finally detected by one of the detectors, leading to the generation of a W state. In addition, the numerical simulation indicates that the fidelity of the prepared state can, for a very wide parameter regime, be very close to unity. 相似文献
20.
A HeNe laser beam is split into four component beams which are subsequently transmitted through four polarization-preserving monomode fibres. At the end of the fibres the emerging beams are coherently recombined in pairs in two steps using inverse beamsplitter cubes. The unavoidable phase differences within each pair of beams, which are caused by temperature and pressure fluctuations in the fibre environment, are detected interferometrically at the fibre ends. Using homodyne techniques, these differences are measured and compensated for by lengthening the optical path in the individual fibres with piezo-electric stretching. With appropriate adjustment of the relative phases the emerging beams can be superimposed onto each other so as to re-form one single coherent beam. 相似文献