Characterization of cu2znsns4 particles obtained by the. The diffraction of light by ultrasonic waves progressing with finite but moderate amplitudes in liquids by kenneth l. 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. 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. A result shows the dependence of various scattered orders on the incident angle. We derive a simple analytical expression for the populations in different diffraction orders.
Anthracene is found to be more efficient than water in this respect while naphthalene and sugar are more efficient than lithium niobate. Measurement of the intensity of progressive ultrasonic. This arrangement is similar to the one which was utilized for examination of ultrasound diffraction of collinear correlated photon pairs within the bragg regime. The structural, morphological, vibrational, raman, optical and electrical properties of codoped and pristine compounds were carried out. Pdf the ramannath equations revisited researchgate.
In the problem of the diffraction of light by a supersonic wave, at normal incidence of the light, the solution of the system of differencedifferential equations of raman and nath, for the amplitudes of the diffracted light beams, is reduced to the integration of. In this article, acoustooptic interaction in raman nath acoustooptic diffraction has been discussed. Analysis and optimum design of a portable qswitch based. 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. A function of 4 variables is defined, which is the solution of the raman nath equations. We present an analytic theory of the diffraction of matter waves by a lattice in the quasibragg regime, by which we. Ramannath diffraction grating national research council. Acoustooptic interaction in ramannath acoustooptic diffraction. Diffraction of light by supersonic waves in solids nature. Raman and nath showed that under certain conditions the ultrasound field can be con sidered as a pure opticalphase grating. Rietveld refinement, morphological, vibrational, raman. Raman nath nonlinear diffraction in second harmonic generation raman nath nonlinear diffraction in second harmonic generation.
Raman nath diffraction, bragg diffraction coherence. Evolution of the nonlinear ramannath diffraction from. 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. Ca and mn cosubstituted bi 1x ca x fe 1x mn x o 3 x 0 and 0.
The raman nath regime is observed at relatively low acoustic frequencies f and a small acoustooptic interaction length l typically, f raman nath acoustooptic diffraction, and a new model of raman nath acoustooptic diffraction is presented. In the last decade, cu2znsns4 czts has been a promising earthabundant, nontoxic candidate material for absorption layers within thinfilm solar cells. Analysis and applications of optical diffraction by gratings. Fraunhofer diffraction, fresnel diffraction, spatial filtering, holography acoustooptic diffraction. Theory of second harmonic generation in a chirped 2d. Aomrn, a compact acoustooptic modulator operating purely in the raman nath diffraction regime, extended the tools employed in laser spectroscopy as optical phase modulators. Osa criterion for bragg and ramannath diffraction regimes. This type of diffraction occurs at an arbitrary angle of incidence. Kirensky institute of physics, krasnoyarsk 660036, russia. 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 diffraction is observed with relatively low acoustic frequencies, typically less than 10 mhz, and with a small acoustooptic interaction length. We present an analysis of atomic diffraction due to the interaction of an atomic beam with a pair of gaussian light pulses. Raman nath light diffraction on acoustophotorefractive holographic gratings that was recorded in cubic photorefractive crystals according to a synchronous detection mechanism was investigated.
Gustavo forte, alberto lencina, myrian tebaldi, and nestor bolognini optical diffraction by inhomogeneous. 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. Applica tions to laserbeam deflection, guidance, modulation, coupling. Osa twodimensional ramannath acoustooptic bistability. Pdf enhancement of nonlinear ramannath diffraction in two. These are raman nath diffraction and bragg diffraction. These are raman nath diffraction and bragg diffraction 4. A compact electron gun for timeresolved electron diffraction. 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. Diffraction of light by sound waves in optically isotropic.
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. 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. Raman nath theory, and amplitude transmittance theory. In this system, feedback is realized by use of a diffracted light beam to control the frequency of the acousticoptic driver. Raman nath diffraction, optimum interaction length, ultimate diffraction efficiency 1. Usually differential methods are employed to account for the light transmitted for volume media. Bragg and raman nath diffraction regimes up to current research in photonics materials. Analysis of kapitzadirac diffraction patterns beyond the.
A method is described for the measurement of the velocity of sound in various liquids, based on the raman nath theory of lightsound interaction. Finally, we present a method to obtain the ramannath acoustooptic diffraction without the optical phase modulations. Zankel an abstract submitted to the school for advanced graduate studies of. Measurement of the intensity of progressive ultrasonic waves by means of raman nath diffraction. Diffraction of collinear correlated photon pairs by an. Diffraction of light by two ultrasonic beams of frequency. In case of the raman nath diffraction, however, greater parallelism of the photon beam is required and bigger diameter of this.
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. Based on a generating function method, an analytical expression for the raman nath like diffraction has been derived and compared with earlier work. Ramannath approximation for diffraction of atom in the laser field of. Download scientific diagram a ramannath diffraction regime b bragg diffraction regime from publication. 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. The device is made from a planar slab optical waveguide material transmissive to light.
The diffraction of light by ultrasound has been measured at 53 mhz in anthracene, naphthalene, and sugar. The intensity of light diffracted by the diffraction grating is 10. A method is presented for measuring the ramannath parameter by an acoustically diffracted lightbeam of one acoustic wavelength width. Mixed phase and absorption thin gratings diffraction. Raman nath diffraction is modified differently with respect to the geometrical and structural. We investigate the effects of geometrical and structural disorders on perfectly asymmetric diffraction pad in raman nath regime.
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. 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. Theory of second harmonic generation in a chirped 2d nonlinear optical superlattice under nonlinear raman nath diffraction andrey m. These are a system of infinite coupled differential equations used to describe the diffraction of light from acoustic waves or thick. The model is based on the individual and simultaneous occurrences of phasegrating diffraction and the doppler effect and optical phase modulation and photonphonon scattering. 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. 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.
An optical wavelength selective device is provided that is particularly useful as a demultiplexer. Acoustic attenuation has also been measured in anthracene over a frequency range of 10 to 150 mhz. 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. 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. Nath1 later solved this equation, and found a limited. Measurement of the intensity of progressive ultrasonic waves by means of raman nath diffraction citation for published version apa. Whitten department of chemistry, university of massachusetts lowell, lowell, massachusetts 01854, usa. A timedependent risk assessment for broken compact fluorescent lamps. Atomwave diffraction between the ramannath and the bragg. Optical diffraction by inhomogeneous volume objects. We show that for grazing incidence, the use of a moving grating can increase the diffraction angle for.
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. The distribution of the energy in each diffractive order follows bessel function1. We investigate ramannath diffraction corresponding to nearbragg diffraction. Pdf atomic diffraction in counterpropagating gaussian. We report the aomrn capacity to be employed as phase modulator in pumpprobe modulation transfer spectroscopy in atomic vapors. The raman nath diffraction pattern can contain many diffraction orders with a symmetrical distribution of light intensity. Sound velocity and diffraction intensity measurements. Pdf we study second harmonic generation via nonlinear ramannath diffraction in an optical superlattice that maintains a periodic modulation of the. 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.
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. The ideal raman nath diffraction slightly deviated when the klein cook parameter was increased from 0 to 1 for low phase delay values and for large phase delay, the characteristics of the bessel function disappeared. 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. Acoustooptic modulators in ramannath diffraction regime. Kapitsadirac scattering problem is solved in ramannath approximation without restrictions on the. Acoustic parameter measurements by acoustooptic diffraction. Observation of ramannath optical diffraction in the phase. Light diffraction by acoustophotorefractive dynamic. 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. This is a pdf file that includes some animations in the document. 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. 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. Cerenkov diffraction is defined by the longitudinal quasiphase matching condition, nonlinear raman nath diffraction satisfies only the transverse. Raman nath diffraction by means of thicknessshear oscillating atcut quartz crystal resonator abstract.
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. Finally, we present a method to obtain the raman nath. A compact raman converter for uvvis spectrometers patrick j. Raman nath diffraction is observed with relatively low acoustic frequencies, typically less than 10 mhz, and with a small acoustooptics interaction length. Introduction the features of ramannath rn acoustooptic diffraction are with short interaction length and multiorder diffraction. Raman and nath have obtained a difference differential equation, giving the amplitude of any diffraction line. The plane in which this grating is located can be imaged outside of the acoustic medium and experimentally studied with a photodetector. It was shown that the diffraction efficiency in sillenitetype gyrotropic crystals depended weakly on the incident light polarization and the external electric field strength. Solutions for the wave amplitudes, diffraction efficiencies, and angular mismatch sensitivities are given in transmission geometries for the case of mixed dielectric and. Acoustooptic devices chapter 10 physics 208, electrooptics peter beyersdorf 1. Compact acoustooptic modulator operating in the purely.
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