Optical diffraction by inhomogeneous volume objects. Usually differential methods are employed to account for the light transmitted for volume media. Cerenkov diffraction is defined by the longitudinal quasiphase matching condition, nonlinear raman nath diffraction satisfies only the transverse. Ramannath approximation for diffraction of atom in the laser field of. The distribution of the energy in each diffractive order follows bessel function1. Light diffraction by acoustophotorefractive dynamic. Diffraction of light by sound waves in optically isotropic. The structural, morphological, vibrational, raman, optical and electrical properties of codoped and pristine compounds were carried out. Evolution of the nonlinear raman nath diffraction from near field to far field dongmei liu,1 dunzhao wei,2 min gu,1,yong zhang,2,4 xiaopeng hu,2 min xiao,2,3 and peng han1 1school of physics and telecommunication engineering, south china normal university, guangzhou 56, china 2national laboratory of solid state microstructures, nanjing.
Raman nath theory, and amplitude transmittance theory. The device is made from a planar slab optical waveguide material transmissive to light. Finally, we present a method to obtain the raman nath. By studying the relations between the power of the diffracted light and its origin in the ultrasonic field, we found that the phase of the diffracted light is modulated temporally and spatially by the ultrasonic wave. Acoustic attenuation has also been measured in anthracene over a frequency range of 10 to 150 mhz. Pdf we study second harmonic generation via nonlinear ramannath diffraction in an optical superlattice that maintains a periodic modulation of the. Raman and nath showed that under certain conditions the ultrasound field can be con sidered as a pure opticalphase grating. The coupled wave theory of raman and nath diffraction is extended to the case of thin anisotropic holographic media with grating vector parallel to the medium boundaries. An analog computer program which calculates the intensity of the light scattered into the various diffraction orders has been adapted for use on a digital computer. The raman nath diffraction pattern can contain many diffraction orders with a symmetrical distribution of light intensity. The plane in which this grating is located can be imaged outside of the acoustic medium and experimentally studied with a photodetector.
A method is presented for measuring the ramannath parameter by an acoustically diffracted lightbeam of one acoustic wavelength width. A compact raman converter for uvvis spectrometers patrick j. Acoustooptic interaction in ramannath acoustooptic. We investigate ramannath diffraction corresponding to nearbragg diffraction. We study kapitzadirac diffraction of a boseeinstein condensate from a standing light wave for a square pulse with variable pulse length but constant pulse area. The two types of disorders are realized by introducing random fluctuations in the position and width of onedimensional 1d driven atomic lattices. Raman nath nonlinear diffraction in second harmonic generation raman nath nonlinear diffraction in second harmonic generation. An experiment which uses a planoconvex atcut quartz crystal resonator vibrating in 5th overtone thicknessshear mode the resonant frequency is about 5 mhz as a raman nath diffraction grating is presented. This arrangement is similar to the one which was utilized for examination of ultrasound diffraction of collinear correlated photon pairs within the bragg regime. We investigate the effects of geometrical and structural disorders on perfectly asymmetric diffraction pad in raman nath regime. We show that for grazing incidence, the use of a moving grating can increase the diffraction angle for raman nath diffraction, but not for bragg diffraction. Then the optimum interaction length, the suitable dimensions of the transducer, and the required index difference dominated by the ultrasonic frequency and power for achieving the ultimate efficiency are analyzed. Gustavo forte, alberto lencina, myrian tebaldi, and nestor bolognini optical diffraction by inhomogeneous. Raman and nath have obtained a difference differential equation, giving the amplitude of any diffraction line.
Theory of second harmonic generation in a chirped 2d nonlinear optical superlattice under nonlinear raman nath diffraction andrey m. Measurement of the intensity of progressive ultrasonic waves by means of raman nath diffraction citation for published version apa. Light diffraction by two ultrasonic waves of frequency ratio 1. Osa criterion for bragg and ramannath diffraction regimes. The intensity of light diffracted by the diffraction grating is 10. Analysis of kapitzadirac diffraction patterns beyond the. Raman nath diffraction by means of thicknessshear oscillating atcut quartz crystal resonator abstract. Ca and mn cosubstituted bi 1x ca x fe 1x mn x o 3 x 0 and 0. This is a pdf file that includes some animations in the document.
These are a system of infinite coupled differential equations used to describe the diffraction of light from acoustic waves or thick gratings, or in the theory of the free electron laser, or the interaction of radiation with multilevel systems. Recently one of us1 pointed out that the optical diffraction effects by supersonic waves in solids are to be interpreted on the basis of the raman nath2. Raman nath diffraction our expressions for the optical. These are raman nath diffraction and bragg diffraction 4. Based on a generating function method, an analytical expression for the raman nath like diffraction has been derived and compared with earlier work. Acoustic parameter measurements by acoustooptic diffraction. Analysis and optimum design of a portable qswitch based. Fraunhofer diffraction, fresnel diffraction, spatial filtering, holography acoustooptic diffraction. We present an analysis of atomic diffraction due to the interaction of an atomic beam with a pair of gaussian light pulses. We present an analytic theory of the diffraction of matter waves by a lattice in the quasibragg regime, by which we. A method is described for the measurement of the velocity of sound in various liquids, based on the raman nath theory of lightsound interaction. Compact acoustooptic modulator operating in the purely.
Pdf the ramannath equations revisited researchgate. Raman nath diffraction is observed with relatively low acoustic frequencies, typically less than 10 mhz, and with a small acoustooptic interaction length. Kapitsadirac scattering problem is solved in ramannath approximation without restrictions on the. A partial wave analysis of the vector wave equation describing the propagation of a light wave is given, and analytic solutions of the equation are obtained in the raman nath and bragg regions of diffraction. Finally, we present a method to obtain the ramannath acoustooptic diffraction without the optical phase modulations.
A result shows the dependence of various scattered orders on the incident angle. Rietveld refinement, morphological, vibrational, raman. Acoustooptic interaction in ramannath acoustooptic diffraction. Bragg and raman nath diffraction regimes up to current research in photonics materials. On examination of light diffraction by a monochromatic acoustic wave, two limiting regimes are distinguished first of all the regimes of raman nath and bragg. Solutions for the wave amplitudes, diffraction efficiencies, and angular mismatch sensitivities are given in transmission geometries for the case of mixed dielectric and. Acoustooptic modulators in ramannath diffraction regime. Osa twodimensional ramannath acoustooptic bistability.
A function of 4 variables is defined, which is the solution of the raman nath equations. Atomwave diffraction between the ramannath and the bragg. This type of diffraction occurs at an arbitrary angle of incidence. In case of the raman nath diffraction, however, greater parallelism of the photon beam is required and bigger diameter of this.
Ramannath diffraction grating national research council. As is well known, debye and sears in america and lucas and biquard in france discovered, in 1932, that a beam of light after passing through a supersonic field breaks up into a fan of diffraction. A compact electron gun for timeresolved electron diffraction. It was shown that the diffraction efficiency in sillenitetype gyrotropic crystals depended weakly on the incident light polarization and the external electric field strength. In addition to such classical special cases of diffraction as bragg and raman nath diffraction, we also consider some cases of the diffraction of light by sound in. We derive a simple analytical expression for the populations in different diffraction orders.
Zankel an abstract submitted to the school for advanced graduate studies of. Kirensky institute of physics, krasnoyarsk 660036, russia. We report the aomrn capacity to be employed as phase modulator in pumpprobe modulation transfer spectroscopy in atomic vapors. Pdf enhancement of nonlinear ramannath diffraction in two. In the last decade, cu2znsns4 czts has been a promising earthabundant, nontoxic candidate material for absorption layers within thinfilm solar cells. These are raman nath diffraction and bragg diffraction. Pdf atomic diffraction in counterpropagating gaussian. In this system, feedback is realized by use of a diffracted light beam to control the frequency of the acousticoptic driver. One major issue preventing this type of solar cells from achieving competitive efficiency is impurity phases and structural defects in the bulk of the absorber. We show that for grazing incidence, the use of a moving grating can increase the diffraction angle for. Raman nath diffraction, bragg diffraction coherence.
A detailed analytical study of optical scattering from a parallel ultrasonic setup is presented in which an optical beam is scattered by a surface acoustic wave that. We present an analytic theory of the diffraction of matter waves by a lattice in the quasibragg regime, by which we mean the transition region between the. A timedependent risk assessment for broken compact fluorescent lamps. Raman nath diffraction, optimum interaction length, ultimate diffraction efficiency 1. Evolution of the nonlinear ramannath diffraction from. Diffraction of light by two ultrasonic beams of frequency. Introduction the features of ramannath rn acoustooptic diffraction are with short interaction length and multiorder diffraction. Measurement of the intensity of progressive ultrasonic waves by means of raman nath diffraction.
Raman nath light diffraction on acoustophotorefractive holographic gratings that was recorded in cubic photorefractive crystals according to a synchronous detection mechanism was investigated. The optimal acoustooptic interaction length in raman nath diffraction is investigated by using deliberately designed apparatus working with pure water. Previous studies of raman nath optical diffraction have emphasized the characteristics of the light distribution in either the nearfield or the farfield of the optical phase grating produced by an acoustic beam. Diffraction of collinear correlated photon pairs by an. Characterization of cu2znsns4 particles obtained by the. Perturbations in the form of holes are etched into the slab waveguide cladding or preferably into the core of the waveguide thereby changing the effective refractive index of regions within the core.
Theory of second harmonic generation in a chirped 2d. An optical wavelength selective device is provided that is particularly useful as a demultiplexer. Raman nath diffraction is observed with relatively low acoustic frequencies, typically less than 10 mhz, and with a small acoustooptics interaction length. Whitten department of chemistry, university of massachusetts lowell, lowell, massachusetts 01854, usa. In this article, acoustooptic interaction in raman nath acoustooptic diffraction has been discussed. Acoustooptic devices chapter 10 physics 208, electrooptics peter beyersdorf 1. Perturbations in the form of holes are etched into the slab waveguide cladding or preferably into the core of the waveguide thereby changing the effective refractive index of regions within the. Download scientific diagram a ramannath diffraction regime b bragg diffraction regime from publication. Applica tions to laserbeam deflection, guidance, modulation, coupling.
Observation of ramannath optical diffraction in the phase. The diffraction of light by ultrasound has been measured at 53 mhz in anthracene, naphthalene, and sugar. Diffraction of light by supersonic waves in solids nature. Raman nath diffraction is modified differently with respect to the geometrical and structural. Measurement of the intensity of progressive ultrasonic. Measurements were taken of 1 order diffracted light intensities for some raman nath parameter values, as a function of the phase shift between the sound beams. Analysis and applications of optical diffraction by gratings.
The model is based on the individual and simultaneous occurrences of phasegrating diffraction and the doppler effect and optical phase modulation and photonphonon scattering. Light diffraction by ultrasonic pulses at normal incidence is studied as well in the raman nath region low frequencies as in the bragg region high frequencies. From the frequency dependence of the optical transmission characteristics of raman nath acousticoptic diffraction, the dynamic equations and steadystate solutions of a twodimensional raman nath acoustooptic bistable system are derived. However, thin enough gratings will tend to operate in the raman nath regime because the index modulation must be large for a thin grating to produce appreciable diffraction. Anthracene is found to be more efficient than water in this respect while naphthalene and sugar are more efficient than lithium niobate. In this study, for the diffraction of light by acoustic waves in liquids, an equation for the diffracted light intensities was obtained in terms of klein cook parameter using time varying permittivity in maxwells equations.
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