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1.
G. V. Kulak 《Journal of Applied Spectroscopy》1999,66(2):302-305
The specific features are considered of the noncollinear optoacoustic interaction in uniaxial gyrotropic quartz crystals in
an intermeadiate regime of diffraction close to the Bragg regime. A system of equations of coupled waves is presented which
describes the optoacoustic interaction in uniaxial gyrotropic crystals in the Raman-Nath, intermedaite, and the Bragg regimes
of diffraction. The dependences of the diffraction efficiency on the ultrasonic wave intensity, the optoacoustic interaction
length, and on the incident light polarization are investigated. A multispike structure of the Bragg maximum is studied that
appears in accounting for the crystal gyrotropy. A good agreement between the theoretical calculations and the known experimental
results for a quartz crystal is shown.
Mozyr State Pedagogical Institute, 28, Studencheskaya Str., Mozyr, 247760, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii,
Vol. 66, No. 2, pp. 278–281, March–April, 1999. 相似文献
2.
V. N. Belyi G. V. Kulak G. V. Krokh P. I. Ropot O. V. Shakin 《Optics and Spectroscopy》2016,121(3):424-430
Specific features of the acousto-optic diffraction of Bessel light beams propagating in the vicinity of the optical axis of a uniaxial gyrotropic crystal have been investigated. The dependences of the diffraction efficiency on the acousto-optic interaction length, ultrasound power, and polarization state of the incident Bessel light beam have been analyzed using the coupled-wave equations and the overlap-integral method. It is shown that polarization-independent diffraction of Bessel light beams is observed in paratellurite crystals, when the Bragg diffraction efficiency is independent of the polarization state of the incident beam. The physical reason for this diffraction has been established (both theoretically and experimentally) to be simultaneous implementation of two processes of anisotropic scattering, at which the Bragg synchronism conditions are satisfied for orthogonal polarized Bessel beams with elliptical polarization. 相似文献
3.
O. V. Shakin V. N. Belyi M. A. Kazaryan Yu. M. Mokrushin V. I. Sachkov 《Bulletin of the Lebedev Physics Institute》2011,38(8):225-230
The conditions of the acousto-optic interaction in the crystals with gyrotropy are considered. The optimal length of the acousto-optic
interaction and the diffraction efficiency in the gyrotropic direction are calculated. The diffraction efficiency is determined
by the coupled wave method which allows calculation of the field interaction in the gyrotropic crystal [1]. It is theoretically
shown and experimentally confirmed that the diffraction efficiency in the gyrotropic direction is independent of incident
light polarization, when the polarization plane rotates by 45° along the interaction length. 相似文献
4.
Polarization-independent modulation of light in gyrotropic cubic crystals is investigated in the Bragg and intermediate diffraction regimes. It is found that, for crystals with considerable specific rotation, the photoelastic anisotropy is suppressed by the circular anisotropy and the observed diffraction efficiency depends weakly on the polarization azimuth of the incident light. Good agreement is obtained between modulation parameters calculated theoretically on the basis of the coupled wave theory and experimental results for a bismuth silicate crystal in the intermediate diffraction regime. 相似文献
5.
G. V. Kulak 《Technical Physics》1997,42(9):1055-1057
An intermediate regime for the diffraction of light on ultrasound in gyrotropic anisotropic and cubic crystals in an external
electric field is considered. A system of equations of the coupled waves, which describes acoustooptic diffraction in gyrotropic
anisotropic crystals with consideration of the electrically induced optical anisotropy for a strong interaction between light
and ultrasound, is presented. An intermediate regime for the diffraction of light on ultrasound in gyrotropic anisotropic
crystals which is close to the Bragg regime for a weak acoustooptic interaction is studied. It is shown that the diffracted
light is elliptically polarized and that the ellipticity and polarization azimuth of the diffracted wave depend on the anisotropy
of the photoelasticity, the electrically induced anisotropy of the crystal in the external electric field, the gyrotropy,
and the asymmetry of the diffraction structure.
Zh. Tekh. Fiz. 67, 80–82 (September 1997) 相似文献
6.
The amplitude-phase features of an intermediate regime of light diffraction on ultrasound in gyrotropic cubic crystals have been investigated. It is established that in the gyrotropic medium excited by ultrasound two coupled phase lattices of photoelasticity appear as a result of the rotation of the polarization planes of interacting waves. These lattices determine the polarization and energy characteristics of a diffracted light. For a gyrotropic cubic crystal of bismuth germanate, good agreement between the theoretical and experimental dependences of the efficiency of diffraction on the ultrasonic intensity in the intermediate regime close to the Bragg regime of diffraction is obtained. 相似文献
7.
A theoretical investigation is carried out for an intermediate regime of optoacoustic interaction, close to the Bragg one,
by ultasonic Rayleigh surface waves in gyrotropic planar waveguides in an external electric field. A system of equations of
associated waves is presented which describes the planar optoacoustic interaction in intermediate, Raman—Nath, and Bragg regimes
of diffraction by ultrasonic surface waves in gyrotropic crystals with electrically induced anisotropy. It is shown that the
intermediate (transition) regime of optoacoustic interaction, which is characterized by an angular selectivity and by the
presence of several diffraction maxima, is the basic regime of diffraction. In this case diffracted light is generally elliptically
polarized with an ellipticity and polarization azimuth that depend on the external electric field intensity.
Translated from Zhurrnal Prikladnoi Spektroskopii, Vol. 66, No. 1, pp. 30–35, January–February, 1999. 相似文献
8.
An intermediate regime of light diffraction by ultrasound propagating along the [001] and [110] axes of a gyrotropic cubic bismuth germanate crystal is investigated. The possibility of polarization-independent light modulation in the intermediate regime of diffraction close to the Bragg regime is shown. The dependences of the diffraction efficiency on the incident light polarization azimuth at different ultrasonic wave intensities are given. 相似文献
9.
G. V. Kulak 《Journal of Applied Spectroscopy》2000,67(3):510-516
The features of the Bragg diffraction of Gaussian light beams at ultrasound waves in gyrotropic crystals were investigated.
The dependence of the diffraction efficiency on the intensity of an ultrasound beam, the cross-section radius of a light beam,
and their divergence ratio was found. An asymptotic expression for the transverse distribution of a diffracted beam was derived.
The crystal gyrotropy has been found to affect significantly the change in the amplitude profile of the diffracted light at
ultrasound frequencies of f ∼ 102–103 MHz. The maximum diffraction efficiency in the gyrotropic medium is shown to be reached at a certain ratio between the divergences,
ultrasound intensity, and specific gyration of the crystal.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 3, pp. 370–374, May–June, 2000. 相似文献
10.
G. V. Kulak 《Journal of Applied Spectroscopy》1997,64(3):428-432
The intermediate regime of optoacoustic interaction, similar to the Bragg one, with Rayleigh surface ultrasonic waves in gyrotropic
planar waveguides is studied. A system of equations of bound waves is presented that describes planar optoacoustic interaction
in the intermediate, Raman-Natoh, and Bragg regimes of light diffraction by surface ultrasonic waves. It is shown that the
optical activity of a wavequide film favors the incident light energy pumping to diffracted light for a TE-polarization wave
and decelerates this process for an incident TM-polarization wave.
Mozyr' State Pedagogical Institute, 28, Studencheskaya St., Mozyr', 247760, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii,
Vol. 64, No. 3, pp. 412–416, May–June, 1997. 相似文献
11.
The intermediate regime of light diffraction on acoustophotorefractive holographic gratings written in cubic photorefractive crystals according to the synchronous-detection mechanism is studied. It is shown that the diffraction efficiency in sillenite-type gyrotropic crystals only slightly depends on the incident light polarization and the external electric field. The highest diffraction efficiency in nongyrotropic crystals was achieved for p-polarized writing and reading light and at a considerable external electric field strength. 相似文献
12.
T. V. Nikolaenko 《Journal of Applied Spectroscopy》2008,75(3):348-352
Oscillation conditions were determined for acoustically distributed feedback (ADFB) lasers based on gyrotropic uniaxial and
cubic crystals. The lasing threshold was shown to be higher for the modes with clockwise polarization than for those with
counterclockwise polarization. It is established that the regions of maximal amplification for clockwise (counterwise) waves
of the gyrotropic crystal are displaced in the direction of decreased (increased) phase detuning, respectively, relative to
amplification regions that correspond to the absence of crystal gyrotropy. The ADFB laser was shown to be capable of generating
at the Bragg frequency.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 3, pp. 331–335, May–June, 2008. 相似文献
13.
A program for calculating characteristics of acousto-optic interaction in biaxial crystals is developed and used to analyze light diffraction by ultrasound in an iodic acid crystal. Crystal cuts with maximum acousto-optic figures of merits are found. It is shown that in the region of the optical axes the frequency dependences of the Bragg angles under anisotropic diffraction are substantially different from those in uniaxial crystals. 相似文献
14.
T. Yamamoto M.-S. Choi S. Majima T. Fukuda T. Kakeshita 《The European physical journal. Special topics》2008,158(1):1-5
Light diffraction in acoustic fields created by
wedge-shaped and parabolic piezoelectric transducers is theoretically
investigated. It is shown that the acoustic fields have a complicated
amplitude-phase structure changing with the acoustic frequency. Principal
characteristics of acousto-optic interaction are examined. It is
demonstrated that the diffraction efficiency in the Bragg regime can
approach 100% in spite of a noticeable phase mismatch. 相似文献
15.
Aranya B. Bhattacherjee 《Optics Communications》2009,282(17):3641-948
We investigate the interaction between a single mode light field and an elongated cigar shaped Bose-Einstein condensate (BEC), subject to a temporal modulation of the trap frequency in the tight confinement direction. Under appropriate conditions, the longitudinal sound like waves (Faraday waves) in the direction of weak confinement acts as a dynamic diffraction grating for the incident light field analogous to the acousto-optic effect in classical optics. The change in the refractive index due to the periodic modulation of the BEC density is responsible for the acousto-optic effect. The dynamics is characterised by Bragg scattering of light from the matter wave Faraday grating and simultaneous Bragg scattering of the condensate atoms from the optical grating formed due to the interference between the incident light and the diffracted light fields. Varying the intensity of the incident laser beam we observe the transition from the acousto-optic effect regime to the atomic Bragg scattering regime, where Rabi oscillations between two momentum levels of the atoms are observed. We show that the acousto-optic effect is reduced as the atomic interaction is increased. 相似文献
16.
17.
We show that layers of acousto-optic gyrotropic paratellurite crystals perturbed by ultrasound can be used as efficient light
modulators in transmission and reflection mode. We have established that the relative intensities of the diffracted waves
are determined by the ratio of the refractive indices of the bounding media, the intensity of the ultrasound, and the thickness
of the modulated layer. We show that for an asymmetric diffraction structure, efficient acousto-optic conversion is possible
in reflection mode, and the weak effect of the gyrotropy is due to its suppression by Fresnel reflection at the boundaries
of the layer.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 6, pp. 819–823, November–December, 2006. 相似文献
18.
The article is devoted to theoretical analysis of light diffraction in a non-homogeneous acoustic field created by a wedge-shaped piezoelectric transducer. Relationships describing electrical, acoustic and acousto-optic properties of the acousto-optic cell are derived in the approximation of a small thickness of the piezoelectric plate. Principal characteristics of acousto-optic interaction are examined such as dependences of the light diffraction efficiency on the phase mismatch and the acoustic wave amplitude. It is shown that the acoustic field has a complicated amplitude-phase structure changing with the acoustic frequency. It is demonstrated that the diffraction efficiency in the Bragg regime can approach 100% in spite of a noticeable phase mismatch. The appropriate optimal values of ultrasound power and incidence angles of light are found. 相似文献
19.
R. S. Akopyan A. V. Galstyan G. G. Zakharyan N. F. Vardanyan Yu. S. Chilingaryan 《Technical Physics》2006,51(6):752-757
The diffraction and polarization properties of thick anisotropic holographic gratings recorded in polymer-dispersed liquid crystals are studied experimentally and theoretically. Such gratings are anisotropic and sensitive to temperature variations and also exhibit a strong dependence of the diffraction properties on the incident radiation polarization because of the presence of liquid-crystal molecules. The dependences of the diffraction efficiency and diffracted beam polarization orientation on the diffraction grating temperature and incident beam linear polarization are obtained for the case of Bragg incidence. The same dependences are derived using the known experimental temperature curves of the liquid crystal permittivity. The experimental data are in agreement with the theoretical calculations. The feasibility of controlling the diffraction characteristics of the grating in a wide temperature interval is demonstrated. 相似文献
20.
The propagation of multiple mutually incoherent spatial solitons in biased photovoltaic–photorefractive crystals is investigated
under steady-state conditions. It is shown that incoherently coupled bright–dark hybrid screening–photovoltaic soliton families
can be established in the crystals provided that the mutually incoherent incident beams have the same polarization and the
same wavelength. Relevant examples are presented where the photovoltaic–photorefractive crystal is taken to be lithium niobate.
Received: 15 May 2000 / Revised version: 27 July 2000 / Published online: 5 October 2000 相似文献