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- Lasers (2)
- Absorption (1)
- Differential equations (1)
- Dye lasers -- Performance (1)
- Dye lasers -- Polarization effects (1)
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- Field theory (Physics) (1)
- Free electron lasers (1)
- Light amplifiers (1)
- Optoelectronic devcies -- Mathematical models (1)
- Oscillation (1)
- Outgassing (Low pressure environments) (1)
- Perturbation (Mathematics) (1)
- Perturbation (Quantum dynamics) (1)
- Semiconductor lasers (1)
- Tides -- Influence of topography on (1)
- Tides -- Mathematical models (1)
- Transients (Dynamics) (1)
Articles 1 - 6 of 6
Full-Text Articles in Engineering
Green's Law Revisited: Tidal Long-Wave Propagation In Channels With Strong Topography, David A. Jay
Green's Law Revisited: Tidal Long-Wave Propagation In Channels With Strong Topography, David A. Jay
Civil and Environmental Engineering Faculty Publications and Presentations
Green's Law states that tidal long-wave elevation ζ and tidal transport Q vary with width b and depth h according to ζ ≌ b−1/2h−1/4 and Q ≌ b+1/2h+/4. This solution is of limited utility because it is restricted to inviscid, infinitesimal waves in channels with no mean flow and weak topography (those with topographic scale L ≫ wavelength λ). An analytical perturbation model including finite-amplitude effects, river flow, and tidal flats has been used to show that (1) wave behavior to lowest order is a function of only two nondimensional parameters representing, respectively, …
Field-Equation Approximations And Amplification In High-Gain Lasers: Numerical Results, Lee W. Casperson
Field-Equation Approximations And Amplification In High-Gain Lasers: Numerical Results, Lee W. Casperson
Electrical and Computer Engineering Faculty Publications and Presentations
It has recently been shown that a field-equation time-derivative approximation that is commonly used in studies of laser-oscillator dynamics is not necessary and can lead to significant errors for some lasers. A related space-derivative approximation is widely used in studies of steady-state laser amplifiers. A more rigorous amplifier formalism is developed here, and the results are exact solutions of Maxwell’s equations. The improved model predicts a spatial instability, single mirror oscillation, and other interesting field behavior.
Field-Equation Approximations And Amplification In High-Gain Lasers: Analytical Results, Lee W. Casperson
Field-Equation Approximations And Amplification In High-Gain Lasers: Analytical Results, Lee W. Casperson
Electrical and Computer Engineering Faculty Publications and Presentations
In a related study the equations governing a high-gain laser amplifier have been solved numerically without making the usual slowly-varying-amplitude derivative approximation in Maxwell’s equations, and thus the field amplitudes are not restricted to vary negligibly in a distance of one wavelength. The results reveal an instability that involves reflections and oscillatory growth of perturbations away from steady state. In the present study steady-state solutions of the field equations are obtained analytically, and transformations are described for converting the equations to alternative intensity-equation sets. These intensity equations are linearized and solved for the growth rate and oscillation period of the …
Pump Polarization Effects In Cw Dye Lasers, Lee W. Casperson, W. J. Sandle, A. C. Wilson, D. M. Warrington, R. J. Ballagh
Pump Polarization Effects In Cw Dye Lasers, Lee W. Casperson, W. J. Sandle, A. C. Wilson, D. M. Warrington, R. J. Ballagh
Electrical and Computer Engineering Faculty Publications and Presentations
The effects of pump polarization on the performance of cw dye lasers have been investigated. A recently developed semiclassical model for synchronously pumped mode‐locked dye lasers is adapted to the problem of cw dye‐laser oscillation, and analytic expressions are obtained for the relationship between the pump power, pump polarization, and dye‐laser output power. The theoretical results are compared with experimental data obtained using an argon‐laser‐pumped rhodamine 6G dye laser.
Field-Equation Approximations And The Dynamics Of High-Gain Lasers, Lee W. Casperson
Field-Equation Approximations And The Dynamics Of High-Gain Lasers, Lee W. Casperson
Electrical and Computer Engineering Faculty Publications and Presentations
Semiclassical models for laser-dynamics studies typically incorporate a derivative approximation that reduces the second-order wave equation for the electric field to a first-order equation. It is shown here that this approximation and further frequency approximations are not necessary and may lead to significant errors for some high-gain laser systems. A more exact analysis also reveals a partial decoupling of the electric and magnetic fields that occurs with fast transient phenomena. These ideas are illustrated in terms of well-known dynamical effects.
A Mathematical Model For Outgassing And Contamination, W. Fang, M. Shillor, E. Stahel, E. Epstein, C. Ly, J. Mcniel, Edward D. Zaron
A Mathematical Model For Outgassing And Contamination, W. Fang, M. Shillor, E. Stahel, E. Epstein, C. Ly, J. Mcniel, Edward D. Zaron
Civil and Environmental Engineering Faculty Publications and Presentations
A model for the mathematical description of the processes of outgassing and contamination in a vacuum system is proposed. The underlying assumptions are diffusion in the source, convection and diffusion in the cavity, mass transfer across the source-cavity interface, and a generalization of the Langmuir isotherm for the sorption kinetics on the target. Three approximations are considered where the asymptotic behavior of the model for large time is shown as well as the dependence and sensitivity of the model on some of the parameters. Some numerical examples of the full model are then presented together with a proof of the …