In previous decades, significant efforts have been devoted to increasing the magneto-optical efficiency of iron garnet materials for the miniaturization of nonreciprocal devices such as isolators and circulators. Elemental substitutions, or proper nanostructuring to benefit from optical resonances, have been pursued. However, all these approaches still require film thicknesses of at least several tens of microns to deliver useful device applications, and suffer from narrow bandwidths in the case of optical resonance effects. This paper reports on a newly discovered enhancement of the Faraday effect observed experimentally in nanoscale bismuth-substituted iron garnet films. It is shown here that this enhancement is not due to elemental substitution or compositional variations, nor is it due to photon trapping or resonance effects. Comprehensive experimental and theoretical analysis of the Faraday rotation reveals a dramatic sevenfold amplification in the magneto-optic gyrotropy within only 2 nm of the air–surface interface, corresponding to just a couple of atomic monolayers as a result of symmetry breaking at the air–film interface. This finding opens up an avenue to the application of monolayer magnetic garnets for the control of light.
15 June 2007 in Journal of the Optical Society of America B
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All-dielectric metasurfaces have been attracting much attention. Low optical losses and a huge variety of optical modes provide unique possibilities for light manipulation at the nanoscale. Recent studies showed that the magneto-optical effects in such metasurfaces are enormously enhanced. Moreover, it is possible to observe novel magneto-optical effects that are absent in smooth films. Excitation of particular photonic resonances makes it possible to design the magneto-optical interaction by the metasurface design. This opens up broad opportunities for magneto-photonic metasurface applications, including optomagnetism, light modulation, sensing, magnetometry, etc.
We report on the experimental implementation of topological edge-state arrays with power confinement in the edge state as high as 29 dB relative to its farthermost channel. Average insertion losses of
A theoretical model for single-defect one-dimensional magnetic photonic crystals with combined linear and circular birefringences is presented. The model elucidates the polarization response of waveguide magnetophotonic crystals and predicts a spectrally asymmetric transmittance detuning from the Bragg frequency. The key components of the model are (a) the presence of two orthogonal elliptically polarized normal modes propagating at different speeds and (b) resonant transmission of these modes through the photonic crystal. Analytical expressions for the normal mode vector field amplitudes and their transmittance through the photonic crystal are obtained. The model predicts a significant nonreciprocal rotation in the presence of linear birefringence levels that would normally suppress the Faraday rotation in ordinary optical channels. Agreement is found with transfer matrix simulation predictions.
24 October 2019 in Journal of Lightwave Technology