Showing papers on "Guided wave testing published in 1980"

Wavelength monitoring of single-mode diode laser using guided-wave interferometer

Abstract: A new technique for continuous monitoring of the output wavelength of single-mode diode lasers is reported. In this approach, a small portion of laser output is coupled into a all-single-mode fiber interferometer. Observation of interferometer outputs can be directly and uniquely related to the output wavelength and its temporal variation. In preliminary results we could trace the behavior of the output wavelength as a function of temperature with an accuracy of about 5 A.

Acoustic guided wave devices

Abstract: An acoustic guided wave device has a wave guiding volume (20) which may include transducer elements (22-25) and other metal elements (26), sandwiched between two acoustic half spaces (10, 12) having acoustic velocity faster than the effective acoustic velocity of the material within the wave guiding volume.

Optical Probing of HF Guided Wave Surface Displacements with Arbitrary Profile

Abstract: 125 I guide with a cladded core geometry,” d p p l . Phvs. l ,ert . , vol. 26, [271 K. Sezawa and K . Kanai, “The range of possible existence o f p. 31, 1975. Stoneley-waves and some related problems,” Bull. Earthquake D. A. Lee and D. M. Corbly, “Use of interface waves for nondeRes. Inst., vol. 17, p. 1, 1939. structivc inspection,”/EE,E Trans. Sonics Ultrason., vol. SU-24, [281 J. G. Scholte, “The range of cxistence of Rayleigh and Stoneley p . 206, 1977. waves,” R . Astron. Soc. London Monthly Notices Geophys. R . 0. Claus and C. H . Palmer, “Direct measurement of ultraSuppl., vol. 5 , p. 120, 1947. sonic Stoneley waves,” Appl . Plrys. L e t t . , vol. 31, p. 547. [29] J. G . Scholte, “On the Stoneley wave equation,” parts I and 11, 1977. Proc. Ned. Akad. V. Wetensch. Amst., vol. 45, pp. 20, 159. R . 0 . (’laus, “Laser probe detection of Stoneley wave interac1942. tions with material boundary defects,” presented at First Intl. 1301 J. G. Scholte, “On surface waves in a stratified medium I .” vol. Syrnp. Lltrason. Matls. Charact., Gaithersburg, MD, 1978. 45, p. 380; “On surface waves in a stratified medium 11,” vol. 45, R . 0. Claus, “Bonded interfacc surface testing via differential inp. 449, in Afdeeling .Wafutrrkrrnde Proc. Amsterdam: Akademie tcrfcromctric Stnnclcy wave measurenlcnts,”Proc. SP/E, vol. Wetenschappen, 1942. 192, 1979. 131 I R. Yarnaguchi and Y. Sato, “Stoneley wave-Its velocity, orbit. R. 0. C‘laus and R. A. Kline. “Adhesive bondline interrogation usand the distribution of amplitude,” Bull. Earthquake Res. Inst., ing Stoneley wave methods,” J. A p p l . P h ~ j s . , Vol. 50, p . 8066. vol. 33, p. 549, Tokyo, 1955. July 1979. 132) A. S. Ginzbarg and E. Strick, “Stoneley wave velocities for a W. L.. Pilant, “Complex roots of the Stoneley-wave equation,” solid-state interface,”Bull. Seismol. Soc. A m . , vol. 48, p. 51, Bull. Seismol. Soc. A m . , vol. 62, p. 285, 1975. 1958. C. Lardat, J. P. Menot, and P. Tournois, “Delay lines using inter[33 I T. C. Lirn and M. J . P. Musgrave, “Stoneley waves in anisotropic facial waves in solid-liquid-solid structures,” IEEE Trans. Sonics media,”Nuture. vol. 225. p. 372, 1970. Ultrason., vol. SU-22, p . 16. 1975. [34j P. Chadwick and P. K . Currie, “Stoneley waves at an interface beR. Stoneley, “Elastic waves a t the surface of separation of two tween elastic crystals,” Quart. J. Mech. Appl. ,%?h., vol. 27, p. solids,” Proc. Ro)?. Soc., vol. 106, p. 416, London, 1924. 497, 1974. K . Sezawa and K . Kanai, “Anomalous dispcrsion of clastic sur[35] G. S. Murty, “Wave propagation at an unbounded interface beface waves l l , ” Bull. Earthquokc Res. Inst.. vol. 16, p. 683, tween two elastic half-spaces,”J. Acoust. Soc. A m . , vol. 58, p. Tokyo, 1938. 1094. 1975. K . Sezawa and K . Kanai. “The forrllation of houndary waves at 1361 A. R. Banghar. G . S. M u r t y . and I . V. V. Raghavachargulu, “On the surfacc o f 2 discontinuity u.ithin the earth’s crust.” Bull. the parametric model of loose bonding of elastic half spaces,”J. Earthquake Res. I n s t . , vol. 16. Q . 504, Tokyo, 1938. Acoust. Soc. A m . , vol. 60, p. 1071, 1976.

High-efficiency generation of 2nd harmonic in-plane waveguides

Abstract: Trapping of electromagnetic energy in an optical waveguide is a good condition for second harmonic generation, owing to the energy confinement along the guided beam However, this advantage is drastically reduced by the difficulties for phase-matching obtention, and by the small overlap between non linear polarization and harmonic wave For the case of Ga As infrared waveguides (fundamental vacuum wavelength = 106 μm), we study a solution based on an extension of Ito and Inaba's suggestion for waveguides in the visible range Basically the deposition of an amorphous Silicon film upon the Ga As guide breaks harmonic guided wave and non linear induced polarization orthogonality allowing thus an overlapping integral enhancement of two orders of magnitude

Eigenmode analysis of leaky dielectric optical waveguides: planar hollow structure

Abstract: We report a wave-optical analysis of light propagation along leaky waveguides using a symmetric hollow dielectric slab as a model. The field deformation due to leakage into the surrounding regions for a guided wave that penetrated into the hollow structure is studied by using the eigenmode expansion method, where the propagation is described by an integral over the modes of the continuum. The numerical evaluation of the integral expansion enables us to estimate the radiation loss for the incident wave. Results are compared with those based on the simplified zigzag ray-optics approach and complex leaky waves.

Guided-Wave Acousto-Optical Devices On Silicon

Abstract: Silicon substrate is attractive for many guided-wave optical devices because of its superb electronic properties and the broad spectrum of fabrication technologies available. Acousto-optic interaction can provide active electro-optical functions for those devices on the electro-optically passive substrate. Hybrid material technologies such as the deposition of oriented ZnO thin film and the deposition of thin films with high photoelastic coefficients are employed for the generation of surface acoustic waves and for the preparation of optical waveguides for acousto-optic interaction. The performances of such devices are limited by surface acoustic wave propagation loss, by the acoustic wave dispersion on multi-layered structure, by restricted optical aperture dimension, and by the electromechanical conversion efficiency of the thin film piezoelectric element. The discussion involves a number of guided-wave acousto-optic devices with applications ranging from RF spectrum analysis, acousto-optical filtering, to optical interferometry.

Analysis of acoustic prism couplers for rayleigh and lamb waves

Abstract: The prism coupler has long been used for excitations of Rayleigh and Lamb waves. Since analysis is lacking in the leaky wave phenomenon on the guided wave path due to the prism perturbation, many problems are not explained. In this paper, the solid and liquid prism couplers are analyzed by the leaky wave concept and modeconversion theory, the following problems are clarified: the mode conversion efficiency expected to be obtained in theory, the coupling length between the prism and the guided wave path as related to the mode-conversion efficiency, the difference between the p- and sv-wave in the solid prism coupler, the effect of the liquid couplant, and the effect of the absorption loss in the prism material. Three of the universal diagrams are also provided. It is confirmed that the measured and theoretical available conversion efficiency for the Rayleigh wave transducer consisting of the bulk wave transducer are in good agreement.

Electrodynamics of a resistive sheet moving inside a wave-guide

Abstract: The interaction between a guided wave and a gliding metal sheet is investigated. The Hertz and Fitzgerald superpotentials are resorted to along with the Lorentz transformation and the overall electromagnetic field is obtained.