Electromagnetic Fields and Currents on Conducting Bodies Excited by Modulated Laser Light - Parts 1 & 2

Abstract

Abstract : A modulated laser beam incident upon a conducting surface can cause electrons to be emitted which in turn causes time harmonic electromagnetic fields. In this two-part report we describe an analysis of the electromagnetic interaction of modulated laser light and selected conducting structures. In Part I the interaction of laser-induced electromagnetic fields with conducting surfaces containing narrow slots is investigated. Integral equation methods have been developed to determine the electromagnetic response of such structures to the modulated laser light. Coupling to several slotted structures of interest is investigated. It has been found that for the laser-light excitation, scattering and penetration characteristics result that are markedly different from those expected for more traditional excitations. In Part II, techniques are described that enable one to compute the voltage at a load impedance terminating a coaxial waveguide whose center conductor protrudes into an open-ended cylindrical tube. The finite-length tube may be empty or it may be partially filled with a dielectric insert. Also, the axial electric field at the focal point of a parabolic reflector is found. Computed results are supported by measurements.