Unidirectional Waveguide Research Articles

Design of unidirectional erbium-doped waveguide ring laser with asymmetric distributed Bragg grating

Proposed is the employment of a second-order asymmetric Bragg grating as an intra-cavity element enabling unidirectional operation of integrated ring lasers. This idea is examined by means of numerical simulations for the case of erbium-doped silica-on-silicon waveguide ring lasers. It is shown that suppression of lasing in one direction can be designed to achieve 20 dB.

Distributed structural characteristic detection system using a unidirectional acoustic waveguide

Apparatus for acoustically analyzing a structure having distributed characteristics comprising a first acoustic waveguide for transmitting an acoustic signal through a portion of the structure, a second acoustic waveguide for receiving a reflected acoustic signature of the structure and transmitting the acoustic signature to a sensor; the sensor producing an output that corresponds to the acoustic signature. The apparatus and methods are particularly adaptable to detecting distributed structural characteristics.

Unidirectional acoustic waveguide system for defect detection in structures : Wu, J.; Spillman, W.B. Smart Materials and Structures, Vol. 4, No. 1, Suppl. A, pp. 62–65 (1995)

Unidirectional acoustic waveguide system for defect detection in structures : Wu, J.; Spillman, W.B. Smart Materials and Structures, Vol. 4, No. 1, Suppl. A, pp. 62–65 (1995)

Unidirectional acoustic waveguide system for defect detection in structures

Many standard nondestructive testing systems utilize ultrasonic pulse echo techniques to locate defects within structures. These techniques rely upon the scattering of acoustic energy by the defects. To locate them usually two or more acoustic detectors are needed. In this paper, an alternate method of structural damage identification is proposed. The technique involves the use of a leaky acoustic waveguide and a unidirectional acoustic waveguide attached to the structure of interest. Only one acoustic detector is required for defect location. An analysis of the concept is provided and experimental results are presented.

Surface acoustic wave technology and applications

Since the advent of the interdigital transduction for efficient transducer of surface acoustic waves (SAW), SAW devices have provided a key technology for communication and signal processing systems. In order to obtain the required electrical terminal characteristics, a diverse number of SAW components have evolved. Some of these components include bidirectional and unidirectional transducers, couplers, beam compressors, waveguides, and reflectors. The various SAW components are monolithically integrated, using processors similar to those for integrated circuits, on a piezoelectric substrate to produce dispersive filters, linear phase filters, resonators, convolvers, and correlators. These devices are manufactured for a wide variety of applications which include TV‐IF, cable TV, VCRs, fiber optic repeaters, radar, spread spectrum receivers, cellular radio, sensors, and a variety of communication receiver applications. The technological innovations and operation of the primary SAW components will be discussed. The presentation will focus on component implementations, their operation, and their most significant parameters. A review of some of the key developments of SAW technology and their applications will also be presented.

Photoinduced conversion of radiation polarization in integrated optics components based on LiNbO/sub 3/

Two photoinduced effects in LiNbO/sub 3/ optical waveguides (unidirectional waveguide mode conversion from ordinary to extraordinary polarization and radiation coupling out of waveguides with polarization plane rotation) are discussed. The circular photovoltaic tensor component in LiNbO/sub 3/ is determined experimentally, and a photovoltaic mechanism to explain photoinduced radiation coupling out of waveguides is proposed. The impact of the effects discovered on the performance of phase modulators is discussed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Some Applications and Characteristics of Ferrite at Wavelengths of 0.87 Cm and 1.9 Cms

This paper describes the use of ferrites in waveguide to produce Faraday rotations at 0.87 cm and 1.9 cms wavelengths. The Dicke radiometric receiver is briefly reviewed and its improvement by the use of ferrite waveguide components is described. Experimental equipment for securing data on the behavior of ferrites is discussed. Details are given for the construction of a unidirectional waveguide transmission line for 0.87 cm wavelength.