共查询到20条相似文献,搜索用时 156 毫秒
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全反射对混合型光纤电流传感器检测灵敏度的影响 总被引:5,自引:0,他引:5
在利用法拉第(Faraday)效应的混合型光纤传感器中,通常用全反射改变光的传递方向,以增加有效光程,并使结构紧凑。反射将改变光的偏振状态,从而影响传感的灵敏度。本文用琼斯(Jones)矩阵方法推导了有反射时传感头的传光特性,分析了反射对检测灵敏度的影响,获得了与实验一致的结果。 相似文献
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采用每毫米1000线的自支撑透射光栅配上背照射软X射线CCD(charge coupled device)组成了透射光栅谱仪,利用北京同步辐射装置(BSRF)3W1B光束线软X射线实验站上X射线源分别对透射光栅的衍射效率和软X射线CCD的响应灵敏度进行了准确的实验标定,获得了150eV到1500eV能区的绝对衍射效率和响应灵敏度的实验结果;同时在国内外研究工作的基础上,发展了自己的透射光栅衍射效率理论计算模型和X射线CCD响应灵敏度计算模型,开展了相应的理论计算和实验标定结果比对工作,理论和实验符合较好, 相似文献
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Masato Suzuki Ken-ichi Fujii Tyuzi Ohyama Hiromi Kobori 《International Journal of Infrared and Millimeter Waves》2003,24(12):2043-2050
We have investigated resonant Faraday effect (RFE), so-called nonlinear Faraday effect, caused by conduction and donor electrons in n-InSb and n-GaAs. Experiments were carried out with using the magneto-optical spectroscopic system combined with two linear polarizers put in before and behind a sample. The rotation angle and the ellipticity for the far-infrared light with elliptical polarization transmitted through the sample were analyzed on the basis of spectra obtained under different experimental configuration for angles between the axes of the polarizer and the analyzer. We have observed some characteristic features associated with RFE in spectra of two samples. Tapping into these features, we could successfully determine the relaxation times and the densities of conduction and donor electrons in the semiconductors. 相似文献
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B. Marx I. Uschmann S. Höfer O. Wehrhan M. Kaluza T. Stöhlker C. Detlefs J. Härtwig 《Optics Communications》2011,284(4):915-918
We report on the measurement of the highest purity of polarization of X-rays to date. The measurements are performed by combining a brilliant undulator source with an X-ray polarimeter. The polarimeter is composed of a polarizer and an analyzer, each based on four reflections at channel-cut crystals with a Bragg angle very close to 45°. Experiments were performed at three different X-ray energies, using different Bragg reflections: Si(400) at 6457.0 eV, Si(444) at 11,183.8 eV, and Si(800) at 12,914.0 eV. At 6 keV a polarization purity of 1.5 × 10− 9 is achieved. This is an improvement by more than two orders of magnitude as compared to previously reported values. The polarization purity decreases slightly for shorter X-ray wavelengths. The sensitivity of the polarimeter is discussed with respect to a proposed experiment that aims at the detection of the birefringence of vacuum induced by super-strong laser fields. 相似文献
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We demonstrate a Mueller polarimeter in which the polarization-state generator and analyzer are both composed of a linear polarizer and two liquid-crystal variable retarders. The polarimeter is designed to optimize the accuracy of the final results by minimization of the condition numbers of the modulation and analysis matrices. The polarimeter calibration, a difficult task by conventional procedures, is achieved easily by use of the eigenvalue method of Compain et al. [Appl. Opt. 38, 3490 (1999)]. The overall polarimeter performance is tested with a linear polarizer at various angles and a compensator at various retardations. 相似文献
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The transmission light intensity method is carried out on a classical platform to study the reciprocity of Faraday effect in water-based Fe3O4 ferrofluid and its diluents. Setting the polarization direction of the analyzer at an angle of 45° to that of the polarizer, the switchable DC magnetic field and the alternating magnetic field are imposed to ferrofluid. The ferrofluid film is replaced by magneto-optical glass for contrastive experiments. The results indicate that ferrofluid is different with magneto-optical glass. Even though the direction of magnetic field is reversed, the rotation direction of the polarized light does not change for ferrofluid. The theoretical model of magneto-optical rotation was used to describe the origin of the reciprocity of Faraday effect in ferrofluid and the non-reciprocity in magneto-optical glass. These findings suggest that the magnetic moments of nanoparticles in ferrofluid tend to the same orientation with the magnetic field because of the rotation of particles. 相似文献
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Hidetoshi Iwamura Shintaro Hayashi Hiroshi Iwasaki 《Optical and Quantum Electronics》1978,10(5):393-398
Using a Y3Fe5O12 crystal as a Faraday rotator material, a samarium cobalt permanent magnet and two iron yokes, a compact optical isolator was constructed at 1.153m for optical transmission systems. The developed isolator is 13 mm in diameter and 25 mm in length, including two polarizers. The isolator characteristics are 1.3 dB forward loss and greater than 30 dB backward loss. A broadband isolator is realized by inserting a 45 degree Faraday rotator and an optically active 45 degree quartz rotator between the two polarizers set at 90 degrees in relation to each other. 相似文献
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M. De Crescenzi L. Papagno G. Chiarello R. Scarmozzino E. Colavita R. Rosei S. Mobilio 《Solid State Communications》1981,40(5):613-617
Very detailed electron energy loss spectra of M2,3 core levels of Cu and Ni in the reflection mode are presented. A careful analysis of the oscillations up to about 300 eV above the edges shows strict analogies to EXAFS and demonstrates that structural information can be obtained with this technique. A comparison with X-ray results above the Cu and Ni K-edges shows that very high accuracy in the radial distribution function can be obtained also with ELS spectra taken above shallow core levels. 相似文献
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Optical limitation in resonant Faraday media sandwiched between crossed polarizers is analyzed both theoretically and experimentally. In this technique resonant Faraday rotation permits a net transmission at low intensity levels, whereas the setup transmission is quenched at higher intensities when the active transition is completely saturated. This technique offers many advantages, such as a very low fluence threshold (~12 nJ/cm(2) in cesium vapor), a high intensity range (more than 4 orders of magnitude for polarizer losses of 10(-5)), and quasi invulnerability to optical damage, which make this technique attractive for the protection of fixed-wavelength operated detectors. 相似文献
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Hongxin Wang Anthony T. Young Jinghua Guo Stephen P. Cramer Stephan Friedrich Artur Braun Weiwei Gu 《Journal of synchrotron radiation》2013,20(4):614-619
X‐ray absorption and scattering spectroscopies involving the 3d transition‐metal K‐ and L‐edges have a long history in studying inorganic and bioinorganic molecules. However, there have been very few studies using the M‐edges, which are below 100 eV. Synchrotron‐based X‐ray sources can have higher energy resolution at M‐edges. M‐edge X‐ray absorption spectroscopy (XAS) and resonant inelastic X‐ray scattering (RIXS) could therefore provide complementary information to K‐ and L‐edge spectroscopies. In this study, M2,3‐edge XAS on several Co, Ni and Cu complexes are measured and their spectral information, such as chemical shifts and covalency effects, are analyzed and discussed. In addition, M2,3‐edge RIXS on NiO, NiF2 and two other covalent complexes have been performed and different d–d transition patterns have been observed. Although still preliminary, this work on 3d metal complexes demonstrates the potential to use M‐edge XAS and RIXS on more complicated 3d metal complexes in the future. The potential for using high‐sensitivity and high‐resolution superconducting tunnel junction X‐ray detectors below 100 eV is also illustrated and discussed. 相似文献
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For the optical polarimeter based on the structure of polarizer–Faraday modulator–analyzer, a novel method of optical rotation measurement was proposed by the waveform analysis of optical intensity signals. The calculation method of the optical rotation was provided by measuring the signal width of the waveform. Furthermore, the optical rotations of sugar solutions with different concentrations were measured by this method, and the fitting degree of obtained fitting curve is 0.9996. This showed that this method was effective. 相似文献
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Magnetic moment of Ni in GdNi single crystal was studied through the soft X-ray absorption spectra (XAS) and the magnetic circular dichroism (MCD) at the Ni L2,3-edges and the Gd M4,5-edges. Our experiment revealed for the first time that the Ni 3d band is not filled completely even at the content of 50 at.% of Gd and the Ni does retain a total magnetic moment coupling antiparallel to that of Gd. This result implied that the Ni in GdNi holds an intrinsic magnetic moment even at 50 at.% of Gd and contradicts the well-known charge transfer model. Further by employing the magneto-optical sum rule, the spin and orbital angular magnetic moment were evaluated and discussed. 相似文献