Leaky waveguide modes along the edge of a dielectric wedge.
It is shown experimentally that a Gaussian beam focused from within a finite wedge onto its edge at an angle of total reflection excites a leaky waveguide mode propagating along the edge. This newly described phenomenon is interpreted in terms of waveguide modes of a tapered dielectric slab of a mode index, which is known to decrease with slab thickness. This decrease in the refractive index leads to a gradual refraction of the incident beam parallel to the edge. A numerical simulation of a focused Gaussian beam incident on a finite dielectric wedge gives a full account of this phenomenon.
Maletzky
Tobias
T
Physikalisches Institut, Westfälische Wilhelms-Universität, 48149 Münster, Germany. t.maletzky@gmx.de
Tanaka
Kazuo
K
Grosjean
Thierry
T
Fischer
Ulrich C
UC