Enhanced Magneto-Optical Activity in Photonic Crystals with Plasmonic Patterns

Olga Borovkova Magneto-Optics, Plasmonics and Nanophotonics group, Russian Quantum Center, Moscow, Russia Nikolai Khokhlov Magneto-Optics, Plasmonics and Nanophotonics group, Russian Quantum Center, Moscow, Russia Mikhail Kozhaev Magneto-Optics, Plasmonics and Nanophotonics group, Russian Quantum Center, Moscow, Russia Department of Theoretical physics, Prokhorov General Physics Institute Russian Academy of Sciences, Moscow, Russia Anatoliy Prokopov Faculty of Physics and Computer Science, Crimean Federal University, Simpheropol, Russia Alexander Shaposhnikov Faculty of Physics and Computer Science, Crimean Federal University, Simpheropol, Russia Vladimir Berzhansky Faculty of Physics and Computer Science, Crimean Federal University, Simpheropol, Russia Ajith Ravishankar Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Mumbai, India Venu Gopal Achanta Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Mumbai, India Anatoly Zvezdin Department of Theoretical physics, Prokhorov General Physics Institute Russian Academy of Sciences, Moscow, Russia Vladimir Belotelov Magneto-Optics, Plasmonics and Nanophotonics group, Russian Quantum Center, Moscow, Russia Department of Theoretical physics, Prokhorov General Physics Institute Russian Academy of Sciences, Moscow, Russia Faculty of Physics, Lomonosov Moscow State University, Moscow, Russia

Multilayer structure consisting of a magnetophotonic crystal with rare-earth iron garnet microresonator layer and plasmonic grating deposited on it was fabricated and studied in order to combine functionalities of photonic and plasmonic crystals. The plasmonic pattern allows excitation of the hybrid plasmonic-waveguide modes localized in dielectric Bragg mirrors of the magnetophotonic crystal or waveguide modes inside its microresonator layer. These modes give rise to the additional resonances in the optical spectra and optical field localization within the structure. It leads to the higher light – magnetic materials interaction and results in the enhancement of the magneto-optical effects. The Faraday effect increases by about 50% at the microresonator modes while the transverse magneto-optical Kerr effect demonstrates pronounced peculiarities at both hybrid waveguide modes and microresonator modes and increases by several times with respect to the case of the bare magnetophotonic crystal without the metal grating. The shape of the TMOKE resonance depends on the type of the waveguide mode that gives rise to the resonance. In some cases, the magnetization mostly influences on the reflectance minima related to the resonances. However, in some other cases the magnetization mostly shifts the spectral position of the waveguide mode resonance.

The studied novel type of heterostructures may find applications in optical signal modulators via external magnetic field or high-sensitive biosensors and magnetic field detectors. Here the advantages of the magnetophotonic crystals with plasmonic gratings are spectral narrowness of optical and magneto-optical resonances and the possibility for their observation in transmission.

The work is supported by the Russian Foundation for Basic Research (projects No 13-0291334, 14-02-01012) and the Russian Presidential Grant MD-5763.2015.2.

o.borovkova@rqc.ru