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Showing papers on "Guided wave testing published in 1970"


Journal ArticleDOI
TL;DR: In this paper, the authors demonstrate the deflection of an optical film-guided wave by a surface acoustic wave by measuring the depletion of the incident optical guided wave, and show that when Bragg conditions are satisfied, 0.18 W acoustic power gives rise to 66% deflection efficiency.
Abstract: The experimental demonstration of deflection of an optical film‐guided wave by a surface acoustic wave is reported. When Bragg conditions are satisfied, 0.18 W acoustic power gives rise to 66% deflection efficiency as measured by the depletion of the incident optical guided wave.

153 citations


Journal ArticleDOI
TL;DR: In this paper, a tunable optical parametric oscillator in a guided wave structure consisting of a thin nonlinear slab asymmetrically sandwiched by two linear dielectrics is treated theoretically.
Abstract: A proposed tunable optical parametric oscillator in a guided wave structure consisting of a thin nonlinear slab asymmetrically sandwiched by two linear dielectrics is treated theoretically. The two linear dielectrics have smaller indices of refraction than the nonlinear dielectric, and the oscillator frequency is tunable by changing the refractive index of one of the linear dielectrics. For a GaAs nonlinear film sandwiched by Irtran 3 or Sapphire and liquid, calculations show that the oscillation frequency can be tuned over ±35% of the subharmonic frequency of a 1.06µ pump as the refractive index of the liquid is varied from 1.25 to 1.6. For reasonable parameters, the threshold power is estimated to be 7 milliwatts. The phase matching conditions and oscillation characteristics for parametric interaction in a guided wave structure are derived and discussed.

30 citations


Journal ArticleDOI
TL;DR: In this paper, the propagation wave analysis of an ultrasonic resonator is extended to include some effects of nonparallelism, guided wave phenomena, and electrical loading, which contributes an "inhomogeneous" broadening to the continuous wave frequency domain response and an ''inhomogenous'' damping to the time domain decay.
Abstract: The ``propagating wave'' analysis of an ultrasonic resonator is extended to include some effects of nonparallelism, guided wave phenomena, and electrical loading. Each of these effects contributes an ``inhomogeneous'' broadening to the continuous wave frequency domain response and an ``inhomogeneous'' damping to the time domain decay. Experimental verification for ultrasound propagating in both thin and bulk solid specimens is obtained by utilizing the sampled‐continuous wave ultrasonic spectrometer. Quantitative evaluation of interference effects among harmonic and inharmonic responses is achieved using the spectrometer in the time domain mode of observation.

11 citations


Patent
Norman J. Dionne1
30 Apr 1970
TL;DR: In this article, phase-focusing means are introduced into a traveling wave electron interaction device to optimize exchange of electron kinetic energy with electromagnetic waves propagated along an adjacent wave-guiding structure by providing an intermediate phase velocity profile at a relatively low level of electron beam energy extraction and well before tube saturation.
Abstract: Phase-focusing means are introduced into a traveling wave electron interaction device to optimize exchange of electron kinetic energy with electromagnetic waves propagated along an adjacent wave-guiding structure by providing an intermediate phase velocity profile at a relatively low level of electron beam energy extraction and well before tube saturation. The resultant redistribution of the guided wave phase velocity provides a delay in the electromagnetic circuit sufficient to permit advancement and desynchronizing of electron bunches to a position in the decelerating field of the propagated waves where the forces on the electrons are substantially minimal. Retention of electrons for longer periods in the decelerating field region of the circuit waves has resulted in a highly significant enhancement in efficiency in traveling wave tube performance. Application of similar phase velocity shift techniques has substantially reduced harmonic frequency power content leading to premature tube saturation in high-gain octave bandwidth devices to yield improvements in efficiency by approximately a factor of 2.

11 citations


01 Feb 1970
TL;DR: In this paper, a year's study carried out by the ESSA/ITS Guided Wave Technology Group under contract from the OHSGT/DOT indicates that low cost, excellent coupling characteristics, and ability to serve vehicles on two closely spaced guideways make the Goubau surface-wave transmission line an attractive solution to the high-speed ground transportation communications problem.
Abstract: A year's study carried out by the ESSA/ITS Guided Wave Technology Group under contract from the OHSGT/DOT indicates that low cost, excellent coupling characteristics, and ability to serve vehicles on two closely spaced guideways make the Goubau surface-wave transmission line an attractive solution to the high-speed ground transportation communications problem. Further testing in a real environment should be undertaken to prove or disprove the encouraging results obtained experimentally with the 918-ft prototype line used in this study. (Author)

2 citations


Journal ArticleDOI
TL;DR: In this paper, the authors present the basis through which the quasi-TEM analysis may be justified for the limit cases of guided waves on microstrip in which the dielectric constant approaches that of free space or becomes very large.
Abstract: The great difficulty in solving for the propagation constant and effective characteristic impedance for microstrip transmission lines is invariably avoided by assuming quasi-TEM propagation and solving Laplace's equation rather than the wave equation. Deschamps and Wu have qualitatively discussed aspects of the hybrid-mode problem. Zysman and Varon have presented a solution for the related but distinctly different problem of closed microstrip. In this communication we present the basis through which the quasi-TEM analysis may be justified for the limit cases of guided waves on microstrip in which the dielectric constant approaches that of free space or becomes very large. The guided wave problem is formulated exactly in terms of longitudinal electric and magnetic field components satisfying the wave equation and coupled through the boundary conditions at the dielectric interface.

2 citations


Journal ArticleDOI
TL;DR: In this article, the authors investigated the propagation of trains of straight crested harmonic waves in infinitely long isotropic, traction free, three-layered plates on the basis of the three-dimensional linear theory of elasticity.
Abstract: : The propagation of trains of straight crested harmonic waves in infinitely long isotropic, traction free, three-layered plates is investigated on the basis of the three-dimensional linear theory of elasticity. It is established, that as in the case of waves traveling in homogeneous plates, the face shear motion and the longitudinal - flexural motion exist uncoupled. However, independent symmetric and antisymmetric modes exist only in the case of three-layered symmetric plates; that is, plates having identical outer layers. The frequency equations have been evaluated numerically. The possibility is discussed of utilizing thin three-layered symmetric strings as delay media in guided wave ultrasonic delay lines having a linear delay versus frequency relation. (Author)

1 citations