I. Theory of the Longitudinal Free Electron Laser. II. A Theoretical Model of the Linear Electrooptic Effect

Author: Shih, Chun-Ching

Year: 1980

Degree: Dissertation (Ph.D.)

Advisor: Yariv, Amnon

Committee Member: Unknown, Unknown

Option: Physics

DOI: 10.7907/c5nd-wr34

Abstract

The first part of this work describes theoretical studies of a proposed longitudinal free electron laser. Stimulated coherent radiation in the infrared region is generated in the proposed laser by a relativistic electron beam passing through a periodically corrugated waveguide. The wavelength of the radiation is widely tunable by changing the electron energy.

Theoretical investigations are based on the single-electron analysis. Both linear and nonlinear treatments of the laser mechanism in a free electron laser are carried out analytically. The phenomena of homogeneous and inhomogeneous interactions, lossy gain, space-charge effect, large-signal behavior, large-gain amplification, and electron dynamics are discussed in detail.

The second part of this work consists of a theoretical study of the linear electrooptic effect. Application of a d.c. or low frequency electric field to a crystal can change its electric susceptibility at optical frequencies. This effect is known as the electrooptic or Pockel's effect. The semiclassical approach used is based on a one-energy gap model, dielectric theory, and the concept of bond-charge. A general expression is obtained for the electrooptic coefficient of a crystal and is applied to the calculation for diatomic and ternary compounds. The results are generally in good agreement with the measured values for nearly all the crystals in which the electrooptic coefficient had been determined.

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