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Articles 1 - 7 of 7

Full-Text Articles in Engineering

Modes Of A Laser Resonator With A Retroreflecting Roof Mirror, Guosheng Zhou, Lee W. Casperson Oct 1981

Modes Of A Laser Resonator With A Retroreflecting Roof Mirror, Guosheng Zhou, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

The self-consistent integral equation for the field distribution of the resonant modes in a resonator with a tilted retroreflecting roof mirror is solved. The field distribution in the direction of the roof can be described in terms of Hermite-Gaussian functions. The beam matrix for a retroreflecting roof is found, and a new type of resonator which does not need precise alignment is proposed.


Experimental Determination Of Post-Buckling Performance Of Steel Angles, Rupasiri Purasinghe Sep 1981

Experimental Determination Of Post-Buckling Performance Of Steel Angles, Rupasiri Purasinghe

Dissertations and Theses

An experimental testing program was conducted to determine the compression member performance in post-buckling region. These results are compared with an analytical computer program developed by Portland State University under Bonneville Power Administration Contract 79-80BP 24005. The paper presents the sensitivity of the performance of single angle compression members to various parameters such as length to radius of gyration ratio, eccentricity, end conditions and yield stress. The effect of local buckling on long member performance is also documented.


Electromagnetic Modes Of An Inhomogeneous Sphere, Lee W. Casperson Aug 1981

Electromagnetic Modes Of An Inhomogeneous Sphere, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

In many cases the electromagnetic modes of a sphere can be obtained exactly. Special simplifications occur when the conductivity, complex permittivity, and complex permeability vary only in the radial direction, and static and time dependent examples are discussed. With quadratic or Coulomblike permittivity variations, the wave functions resemble the quantum mechanical harmonic oscillator or hydrogen atom wave functions, and similar angular momentum operators are obtained.


Synthesis Of Gaussian Beam Optical Systems, Lee W. Casperson Jul 1981

Synthesis Of Gaussian Beam Optical Systems, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Systematic procedures are presented for determining the the optical components needed to obtain an arbitrary transformation of a propagating light ray or Gaussian beam.


Modes Of A Laser Resonator With A Retroreflective Mirror, Guosheng Zhou, Lee W. Casperson May 1981

Modes Of A Laser Resonator With A Retroreflective Mirror, Guosheng Zhou, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

The self-consistent integral equation for the field distribution of the resonant modes in an inclined retroreflective grating resonator is solved in the limit of large Fresnel numbers. The transverse field distribution in the direction perpendicular to the grating grooves can be described in terms of Hermite-Gaussian functions provided that λ « d « w, where λ is the wavelength, d is the grating spacing, and w is the beam spot size.


Laser Broadening Ratio From The Multimode Oscillation Threshold, Lee W. Casperson Apr 1981

Laser Broadening Ratio From The Multimode Oscillation Threshold, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Lasers with mixed line broadening typically oscillate in a single longitudinal mode for excitation levels only slightly above threshold. At high pump levels, less desirable multimode oscillation may sometimes occur. A procedure is described for using the multimode threshold as a sensitive measure of the broadening ratio, and GaAs is mentioned as an example.


The Influence Of Halloysite Content On The Shear Strength Of Kaolinite, Reka Katalin Gabor Jan 1981

The Influence Of Halloysite Content On The Shear Strength Of Kaolinite, Reka Katalin Gabor

Dissertations and Theses

The objective of this thesis is to determine the relative shear strengths of halloysite, kaolinite, synthetic mixtures, and local soils, to investigate the influence of halloysite content on the shear strength of kaolinite, and to explore the possibility that the strength properties of soil clays might be controlled by the relative content of their component minerals.