Analysis of Gaussian beam propagation and diffraction by inhomogeneous wave tracking
Abstract
Inhomogeneous waves behave locally like A(r) exp/ikS(r)/, where A and S are spatially dependent complex amplitude and phase functions, and k is the (large) freespace wave number. A previously developed asymptotic theory for highfrequency propagation and scattering of such waves is applied to the propagation and scattering of paraxial Gaussian beams. Attention is given to Gaussian beams in free space, to beams in a lenslike medium with parabolic variation of the refractive index, and to beam reflection by a cylindrical obstacle. In the latter instance, the obstacle size may be comparable to the incident beamwidth, thereby introducing substantial distortion into the reflected beam. The results obtained from the asymptotic theory are verified by comparison with rigorously derived solutions, thereby confirming the validity of the theory.
 Publication:

IEEE Proceedings
 Pub Date:
 November 1974
 Bibcode:
 1974IEEEP..62.1530C
 Keywords:

 Asymptotic Methods;
 Beams (Radiation);
 Ray Tracing;
 Tracking (Position);
 Wave Diffraction;
 Wave Propagation;
 Circular Cylinders;
 Diffraction Propagation;
 Electromagnetic Wave Transmission;
 Inhomogeneity;
 Normal Density Functions;
 Plane Waves;
 Radiation Distribution;
 Refractivity;
 Statistical Distributions;
 Wave Reflection;
 Wave Scattering;
 Communications and Radar