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Lateral shifts of totally reflected gaussian beams
Author(s) -
Shin S. Y.,
Felsen L. B.
Publication year - 1977
Publication title -
radio science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.371
H-Index - 84
eISSN - 1944-799X
pISSN - 0048-6604
DOI - 10.1029/rs012i004p00551
Subject(s) - optics , physics , beam (structure) , gaussian beam , collimated light , transverse plane , isotropy , m squared , displacement (psychology) , reflection (computer programming) , plane (geometry) , planar , optical axis , gaussian , geometrical optics , beam diameter , geometry , mathematics , lens (geology) , psychology , laser , computer graphics (images) , structural engineering , laser beams , computer science , psychotherapist , programming language , engineering , quantum mechanics
At an interface with incidence‐angle‐dependent reflection coefficient, a highly collimated totally reflected beam experiences a displacement of the beam axis and the phase center from the location predicted by geometrical optics. Studies in the literature of the lateral (longitudinal and transverse) beam shift have produced conflicting results. Here, the shift phenomenon for gaussian beams is analyzed by a rigorous method whereby the high‐frequency point source or line source Green's function solution as expressed in ray‐optical terms is converted into the beam solution by assigning a complex value to the source coordinates. Results obtained for two‐dimensional and three‐dimensional electromagnetic fields at plane isotropic and anisotropic interfaces are compared critically with those found elsewhere. Also included are the lateral shifts at a curved cylindrical boundary, which have not been studied heretofore. These planar and curved geometries are relevant, respectively, to beam coupling into slab and fiber waveguides. Our expressions for the beam shifts are consistent with those required for correct conversion of multiply‐reflected rays or beams in slabs and fibers into guided modes, thereby lending further support to the arguments presented.