Showing papers on "Guided wave testing published in 1977"
TL;DR: In this paper, a highly efficient TE-TM mode conversion device utilizing the acoustooptic effect has been demonstrated, where an acoustic surface wave propagating collinearly with an optical guided wave has been made by an acoustic receiver.
Abstract: A highly efficient TE-TM mode conversion device utilizing the acoustooptic effect has been demonstrated. Mode conversion has been made by an acoustic surface wave propagating collinearly with an optical guided wave. The maximum mode conversion, although the fraction was restricted to 70 percent, has been obtained with an acoustic power of only 55 mW (electrical input 0.55 W). Effective interaction length of the present device is limited to 5 mm due to optical and/or acoustic inhomogeneity of the waveguides. For selecting TE and TM waves, a polarizer is constructed monolithically and the extinction ratio is improved by up to 21 dB. Performance characteristics of a tunable optical filter of this type of the mode conversion are also discussed.
82 citations
TL;DR: The results of measurement made on the devices which employ the first-order acoustic beam steering from six-element phased-SAWs of relatively small total acoustic aperture have shown that accurate tracking of the Bragg condition is achievable for a frequency band of more than 250 MHz.
Abstract: Efficient wideband guided-wave acoustooptic Bragg diffraction has been demonstrated using a phased surface acoustic wave array in Y-cut LiNbO3 waveguides. The results of measurement made on the devices which employ the first-order acoustic beam steering from six-element phased-SAWs of relatively small total acoustic aperture, at the center frequency of 325 MHz, have shown that accurate tracking of the Bragg condition is achievable for a frequency band of more than 250 MHz. In one of the deflectors that employ a larger total acoustic aperture, only 68 mW of electric drive power or 3.5 mW of acoustic power was required to diffract 50% of the light over a bandwidth of 112 MHz. This bandwidth is a nearly sixfold increase over that of the deflector that employs a single SAW of identical aperture. The quality of both deflected and undeflected light beams was very good.
28 citations
TL;DR: In this paper, a detailed wave-optical analysis is presented for the propagation along semileaky-type thin-film optical waveguides, originally proposed by Sosnowski as the polarization mode filter, including an isotropic film and anisotropic substrate with the refractive index relation and the crystal axis orientation arranged so that the guided modes are possible in TE (or TM) polarization only.
Abstract: A detailed wave-optical analysis is presented for the propagation along semileaky-type thin-film optical waveguides This type of waveguide, originally proposed by Sosnowski as the polarization mode filter, includes an isotropic film and anisotropic substrate with the refractive index relation and the crystal-axis orientation arranged so that the guided modes are possible in TE (or TM) polarization only A set of normal modes is derived first, where the modes of leaky polarization form a continuum Next are studied, on the basis of normal-mode expansion, the field deformation and external radiation characteristics of a guided wave of leaky polarization that penetrates into the semileaky structure An efficient polarization-discrimination property is shown for the example of a polyurethane film/calcite substrate configuration A brief discussion is also given to the guided-radiation mode coupling that occurs in a perturbed structure with off-diagonal permittivity tensor elements
13 citations
TL;DR: In this article, the preparation and properties of Langmuir (long-chain fatty acid) films for use as optical waveguides are described, and the refractive index and molecular thickness can be estimated by probing the films with a guided wave.
Abstract: This paper describes the preparation and properties of Langmuir (long-chain fatty-acid) films, for use as optical waveguides. It is shown how the refractive index and molecular thickness can be estimated by probing the films with a guided wave, and how such layers may be utilised to modify the propagation characteristics of pre-fabricated guiding structures. Cases of isotropic and anisotropic guides formed from such films are discussed, together with further uses of such films as cladding to guides and other materials.
12 citations
TL;DR: In this paper, the existence of the Josephson junction behavior of weak links was confirmed by examination of their behavior in applied magnetic fields, and it was shown that weak links can be created by locally weakening the superconductivity of a narrow thin-film lead strip via the evanescent field of an optical guided wave.
Abstract: Superconducting weak links have been created by locally weakening the superconductivity of a narrow thin‐film lead strip via the evanescent field of an optical guided wave. Existence of the Josephson junction behavior of these links was confirmed by examination of their behavior in applied magnetic fields.
11 citations
TL;DR: In this paper, the authors investigated the convolution of two acoustic surface wave (ASW) signals with an optical guided wave and showed that the maximum time-bandwidth product that can be achieved by such a convolver is of the order of 1000 or more.
Abstract: Interaction of two antiparallel acoustic surface waves (ASW) with an optical guided wave has been investigated theoretically as well as experimentally to obtain the convolution of two ASW signals. The maximum time-bandwidth product that can be achieved by such a convolver is shown to be of the order of 1000 or more. The maximum dynamic range can be as large as 83 dB.
9 citations
TL;DR: In this article, the authors used electonbeam generated masks to make iron oxide working masks for photolithographic fabrication of these passive components in Nb2O5 optical waveguides.
Abstract: Thin‐film lenses, mirrors, and diffraction gratings have been fabricated from electon‐beam‐generated masks These masks were used to make iron oxide working masks for photolithographic fabrication of these passive components in Nb2O5 optical waveguides The optical‐waveguide characteristics of these components are discussed
5 citations
TL;DR: In this article, the authors derived expressions for the electric field and refractive index distribution for guided-wave electro-optic structures using strip electrodes, and plots of the resulting field and index distribution are presented for LiNbO, substrates.
Abstract: Analytic expressions for the electric field and refractive-index distribution are derived for guidedwave electro-optic structures using strip electrodes. The electric-field distribution is calculated considering the anisotropy of the electro-optic medium, and plots of the resulting field and index distribution are presented for LiNbO, substrates.