scholarly journals Single Channel Waveguide with Roughness

Author(s):  
Henrich Frielinghaus ◽  
Tetyana Kyrey ◽  
Olaf Holderer
1984 ◽  
Vol 5 (3) ◽  
Author(s):  
J. Čtyroký

SummaryThe potential applicability of multimode integrated optical branching waveguides and couplers is limited primarily by their coupling loss to optical fibers. To get a reasonably detailed theoretical insight, the fiber-to- fiber coupling loss of a section of a multimode channel waveguide fabricated, e.g., by ion exchange in a glass substrate is calculated using a ray-optic approximation. An approach of the length-averaged coupling loss results in a simple and efficient calculation procedure which enables one to optimize the parameters of a channel waveguide for minimum coupling loss. Coupling losses as low as 2 dB and 0.25 dB can be obtained for single channel and sandwich structures, respectively, coupled to standard graded-index fibers.


2001 ◽  
Vol 7 (S2) ◽  
pp. 540-541
Author(s):  
Edward F. Plinski ◽  
Jerzy S. Witkowski

A precise analysis of the biological remains is presented in the paper. A single-channel waveguide carbon dioxide laser is used in a process of ablation ‘ for the exposing of biological remains of mineralised organisms found in a sea slime used as a component in some technological process.Many important applications of the laser base on the process of ablation. These include also so precise biomedical uses like structural studies of biomolecules. Among of the wide range of the laser devices the waveguide carbon dioxide lasers can be used in a precise biological investigations. A single-channel waveguide CO2 laser emits very easy the optical wave formed in a single, so called quasi-Gaussian, mode2. The distribution of the intensity of the laser output radiation in a basic Gaussian mode is shown in Figure 1. A high quality laser output beam in a basic Gaussian mode can be easy focused permitting a precise ablation of the investigated material in a very small area of 100 μm and less.


Author(s):  
P. Trebbia ◽  
P. Ballongue ◽  
C. Colliex

An effective use of electron energy loss spectroscopy for chemical characterization of selected areas in the electron microscope can only be achieved with the development of quantitative measurements capabilities.The experimental assembly, which is sketched in Fig.l, has therefore been carried out. It comprises four main elements.The analytical transmission electron microscope is a conventional microscope fitted with a Castaing and Henry dispersive unit (magnetic prism and electrostatic mirror). Recent modifications include the improvement of the vacuum in the specimen chamber (below 10-6 torr) and the adaptation of a new electrostatic mirror.The detection system, similar to the one described by Hermann et al (1), is located in a separate chamber below the fluorescent screen which visualizes the energy loss spectrum. Variable apertures select the electrons, which have lost an energy AE within an energy window smaller than 1 eV, in front of a surface barrier solid state detector RTC BPY 52 100 S.Q. The saw tooth signal delivered by a charge sensitive preamplifier (decay time of 5.10-5 S) is amplified, shaped into a gaussian profile through an active filter and counted by a single channel analyser.


1968 ◽  
Vol 11 (1) ◽  
pp. 189-193 ◽  
Author(s):  
Lois Joan Sanders

A tongue pressure unit for measurement of lingual strength and patterns of tongue pressure is described. It consists of a force displacement transducer, a single channel, direct writing recording system, and a specially designed tongue pressure disk, head stabilizer, and pressure unit holder. Calibration with known weights indicated an essentially linear and consistent response. An evaluation of subject reliability in which 17 young adults were tested on two occasions revealed no significant difference in maximum pressure exerted during the two test trials. Suggestions for clinical and research use of the instrumentation are noted.


2008 ◽  
Vol 1 (2) ◽  
pp. 139-155 ◽  
Author(s):  
YAEL DARR

This article describes a crucial and fundamental stage in the transformation of Hebrew children's literature, during the late 1930s and 1940s, from a single channel of expression to a multi-layered polyphony of models and voices. It claims that for the first time in the history of Hebrew children's literature there took place a doctrinal confrontation between two groups of taste-makers. The article outlines the pedagogical and ideological designs of traditionalist Zionist educators, and suggests how these were challenged by a group of prominent writers of adult poetry, members of the Modernist movement. These writers, it is argued, advocated autonomous literary creation, and insisted on a high level of literary quality. Their intervention not only dramatically changed the repertoire of Hebrew children's literature, but also the rules of literary discourse. The article suggests that, through the Modernists’ polemical efforts, Hebrew children's literature was able to free itself from its position as an apparatus controlled by the political-educational system and to become a dynamic and multi-layered field.


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