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干涉法测量晶体电光系数实验装置的改进 总被引:7,自引:1,他引:6
用一台泰曼干涉仪,以压电晶体的逆压电效应补偿晶体电光效应所引起的光程变化,提供了一种简单、迅速和高灵敏度测量晶体电光系数的方法. 相似文献
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用干涉仪的方法测量了Ce:BaTiO3晶体的低频电光系数和压电系数.排除压电效应对光通过晶体引起相位的变化,得到低频下经极化的Ce:BaTiO3单晶的电光系数r42=1945±220pm/V和r13=11.8±1pm/V.从而,为研究Ce:BaTiO3晶体的光折变效应和理论计算提供了精确的线性电光系数
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干涉法测量晶体的压电系数 总被引:1,自引:0,他引:1
我们用一台泰曼干涉仪,以DKDP晶体的电光效应补偿由于晶体反压电效应听引起的光程差,提供了一种简单、迅速和高灵敏度测量晶体压电系数的方法. 相似文献
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铁电薄膜物理学与集成铁电学专题研讨会在南京大学举行铁电体是一类具有自发电极化且其极化矢量在外电场作用下反转的电介质,它具有压电、热释电、电光、声光、光折变、非线性光学效应和高介电系数等特性,早就引起材料科学及物理学界的重视。近年来,由于制膜技术和微电... 相似文献
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YANG Shi-Jie ZHAO Hu YU Yue 《理论物理通讯》2005,44(6):1095-1098
When a surface acoustic wave (SAW) propagates on the surface of a GaAs semiconductor, coupling between electrons in the two-dimensional electron gas beneath the interface and the elastic host crystal through piezoelectric interaction will attenuate the SAW. The coupling coemcient is ~alculated for the SAW propagating along an arbitrary direction. It is found that the coupling strength is strongly dependent on the propagating direction. When the SAW propagates along the [011] direction, the coupling becomes quite weak. 相似文献
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YANG Shi-Jie ZHAO Hu YU Yue 《理论物理通讯》2005,44(12)
When a surface acoustic wave (SAW) propagates on the surface of a GaAs semiconductor, coupling between electrons in the two-dimensional electron gas beneath the interface and the elastic host crystal through piezoelectric interaction will attenuate the SAW. The coupling coefficient is calculated for the SAW propagating along an arbitrary direction. It is found that the coupling strength is strongly dependent on the propagating direction. When the SAW propagates along the [011] direction, the coupling becomes quite weak. 相似文献
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Electro-magneto-acoustic SH waves propagating oblique to the periodic layered piezoelectric structures are studied under the coupling of the acoustic wave and the electromagnetic wave. Band structures of the so-called piezoelectric superlattice and phononic/photonic crystal are given both at acoustic frequencies and at optical frequencies. For the periodic layered piezoelectric structures, phonon-polaritons (the coupling modes of the phonons and photons) are found not only happening near the center of the Brillouin zone (in the long-wavelength limit) at acoustic frequencies, but also being able to appear in the whole Brillouin zone at optical frequencies. Appearing of these phonon-polaritons may provide a way to design a new type of acousto-optic devices. 相似文献
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S. Ghosh M.P. Rishi 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,19(2):223-230
The modulation of an intense electromagnetic beam induced by the acousto-optic (AO) effect has been analysed in a transversely
magnetised semiconductor-plasma medium. The effect of carrier diffusion on the threshold field and gain profile of the modulated
wave has been extremely investigated using coupled mode theory. The origin of the AO interaction is assumed to lie in the
induced nonlinear diffusion current density of the medium. By considering the modulation process as a four wave parametric
interaction an expression for effective third-order AO susceptibility describing the phenomena has been deduced. The modulation
is greatly modified by propagation characteristics such as dispersion and diffraction due to dielectric relaxation of the
acoustic mode. The threshold pump field and the steady state growth rates are estimated from the effective third-order polarisation
in the plasma medium. Analytical estimation reveals that in the presence of enhanced diffusion due to excess charge carriers
the modulated beam can be effectively amplified in a dispersionless acoustic wave regime. The presence of an external dc magnetic
field is found to be favourable for the onset of diffusion induced modulational amplification of the modulated wave in heavily
doped regime.
Received 5 November 2001 相似文献
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The influence of the dimension of an acousto-optic cell in the plane orthogonal to the plane of acousto-optic diffraction on the acoustic field structure and, consequently, on acousto-optic diffraction is studied theoretically and experimentally. A method is suggested for approximate calculation of the acoustic field with regard to the acoustic column reflection from the crystal faces. Based on this method, the influence of the acousto-optic cell dimensions is analyzed in a wide range of ratios between the height of the piezoelectric transducer and the height of the crystal. A region of acoustic power concentration is predicted to arise both for parallel faces and for slight wedging. A number of statements are demonstrated with paratellurite used as an interaction medium. The results may be useful in designing acousto-optic devices. 相似文献
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A spatial Fourier transform approach is proposed to investigate the effects of polarization changes and beam profile deformation of light during acousto-optic (AO) interaction in isotropic media. The behaviour of the total scattered optical fields inside the AO cell can be properly described by a vector wave equation of which the permittivity is perturbed by an acoustic wave propagating inside the medium. In the Bragg regime, using a spatial Fourier transform approach, two coupled differential equations can be derived from the wave equation to depict AO interaction in the spatial frequency domain. Analytic solutions, which comprise the effects of changing polarization, beam deformation and propagating diffraction, can be found from the coupled equations. Detailed numerical simulations, including Fourier transforming the incident light profile to calculate the spectra of the scattered light beams and, hence, their profiles in space using the inverse transform, are presented. 相似文献
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The propagation and reflection of bulk ultrasonic waves in a paratellurite crystal have been investigated by the acousto-optic
method. Simultaneous excitation of two acoustic waves by one piezoelectric transducer has been observed in a cell of complex,
specially chosen configuration. Maximally efficient conversion of the energy of a quasi-longitudinal wave into a single reflected
quasi-shear wave with a walkoff angle 72° is implemented for the reflection from a free crystal boundary. The wave beam compression
by a factor of 7 is observed for this reflection. A reflection (close to backward) of waves with an angle of spatial separation
of the incident and reflected beams equal to 8° is also implemented. The acousto-optic figure of merit values of the medium
are calculated for arbitrary propagation and polarization directions of the interacting light and ultrasonic waves. Possible
applications of the effects studied in acousto-optics and acoustoelectronics are indicated. 相似文献
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The features of noncollinear acousto-optic interaction in gyrotropic crystals in the intermediate diffraction regime and the
regime of Bragg diffraction were investigated. The dependence of the efficiency of diffraction in gyrotropic paratellurite,
tellurium, and quartz crystals on the intensity of the ultrasonic wave, acousto-optic interaction length, and incident-light
polarization was investigated. It is shown that the gyrotropy of the crystal is responsible for the appearance of a multiple-peak
structure of the Bragg maximum. It has been established that in the case of propagation of incident and diffracted waves in
the vicinity of the optical axis of the crystal, the diffraction efficiency is independent of the polarization state of the
incident light. The results of theoretical calculations are in agreement with the experimental results obtained for uniaxial
crystals.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 1, pp. 105–110, January–February, 2000. 相似文献
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Anisotropic acousto-optic diffraction in biaxial crystal of alpha-iodic acid has been studied in the case in which the wave vector of the ultrasound is almost orthogonal to one of the optical axes and the directions of incident and diffracted light beams are close to the optical axis. It is shown that, owing to the complex form of wave surfaces in the field of optical axes of a biaxial crystal, the considered variant of acousto-optic interaction is very sensitive to changes in the direction of the wave vector of the ultrasound that imposes special requirements to accuracy of manufacturing of acousto-optic devices. 相似文献