Circuit theory for a class of anisotropic and gyrotropic thin-film optical waveguides and design of nonreciprocal devices for integrated optics

Abstract

A circuit-theoretic treatment is presented for thin-film optical waveguides using a class of real anisotropic and gyrotropic materials. The analysis is based on the two-mode approximation in normal-mode theory. The terminal behavior of those guides is described by the 2 × 2 transmission matrix and expressions for matrix elements of six systems that are introduced as canonical elements in circuit synthesis are derived. Properties of canonical elements are discussed with particular attention on their reciprocity. Using the transmission matrix, we can treat the design of thin-film optical devices by a simple matrix operation familiar in conventional transmission-line circuit synthesis. As a typical application the design of various nonreciprocal integrated-optical devices is treated in detail. The desired response is synthesized by cascading selected canonical elements in an appropriate order. Examples include the gyrator, unidirectional mode converter, differential phase shifter, isolator, and circulator.

Silicon ring isolators with bonded nonreciprocal magneto-optic garnets

“…With a straight waveguide coupled to the ring resonator, the forward light from the input is coupled to the CW mode while the backward light is coupled to the CCW mode. If the transmission spectra for the forward and backward directions are offset by half of the free spectral range, optical The propagation constant difference between CW and CCW modes with existence of an external magnetic field is written as [14,15] …”

Analysis of Integrated Optical Isolator Using a Single Section of Magnetic Garnet Waveguide Layer −on Non-and Reciprocity in Iron-Garnet Waveguides−

“…General treatments as to gyrotropic waveguides have previously been shown by Yamamoto et al [6], [11], Miyazaki et al [12], and Torfeh et al [13]. We here show one approach to the problem of the magnetic garnet waveguides.…”

Nonreciprocal light diffraction by a vortex magnetic particle of spherical shape

“…So, we come to a conclusion that although this estimation is very rough it turns out to be a satisfactory fit to the experiment. The difference is apparently attributed to the different shape of the particle and to the violation of the assumption that the permittivity value is not large (see (24)). …”

“…Note that the intensity of light diffracted by a planar chiral structure does not change with a reversal of the propagation direction, in accordance with the reciprocity law. The non-reciprocal intensity effects can appear only in the presence of a magnetic field [18][19][20] or in magnetic systems [21][22][23][24][25] . Such effects have been observed recently in a two-dimensional lattice of magnetic vortices 26 .…”