Waveguide modes of 1D photonic crystals in a transverse magnetic field

  • PDF / 568,739 Bytes
  • 7 Pages / 612 x 792 pts (letter) Page_size
  • 29 Downloads / 190 Views

DOWNLOAD

REPORT


MOLECULES, OPTICS

Waveguide Modes of 1D Photonic Crystals in a Transverse Magnetic Field D. A. Sylgachevaa,b,*, N. E. Khokhlova,b, A. N. Kalisha,b, and V. I. Belotelova,b aPhysics

Department, Moscow State University, Moscow, 119991 Russia Quantum Center, Skolkovo, Moscow, 143025 Russia *e-mail: [email protected]

bRussian

Received December 21, 2015

Abstract—We analyze waveguide modes in 1D photonic crystals containing layers magnetized in the plane. It is shown that the magnetooptical nonreciprocity effect emerges in such structures during the propagation of waveguide modes along the layers and perpendicularly to the magnetization. This effect involves a change in the phase velocity of the mode upon reversal of the direction of magnetization. Comparison of the effects in a nonmagnetic photonic crystal with an additional magnetic layer and in a photonic crystal with magnetic layers shows that the magnitude of this effect is several times larger in the former case in spite of the fact that the electromagnetic field of the modes in the latter case is localized in magnetic regions more strongly. This is associated with asymmetry of the dielectric layers contacting with the magnetic layer in the former case. This effect is important for controlling waveguide structure modes with the help of an external magnetic field. DOI: 10.1134/S1063776116110236

1. INTRODUCTION Modern requirements to the speed of information transfer and processing by optical methods stimulate the search for new method of light control on the submicrometer scale. Multilayer planar waveguides open new possibilities in this field [1–7]. Planar waveguide systems are used for example, in the fiber-optic communication system of the wavelength division multiplexing (WDN) type for optical modulation in a narrow spectral range corresponding to one of data transmission channels [1–4]. Optical properties of planar waveguides are modified using the Bragg structures, viz., 1D photonic crystals (PCs). In particular, the use of PCs as waveguide shells makes it possible to preset the required dispersion characteristics of eigenmodes [5, 6]. Such structures also considerably extend the range of application of waveguides, including optical switches and Mach–Zander waveguide interferometers [7]. Photonic crystals containing layers of magnetically ordered media, viz., magnetic photonic crystals (MPCs), are of special interest. In this case, the magnetization of the layers modifies either the polarization of a light wave or its phase velocity depending on the orientation relative to the direction of light propagation and the planes of the layers [8–14]. This leads to resonant enhancement of magnetooptical effects [15–18]. It was shown in [15] that the Faraday angle for light passing through the (Bi:YIG/SiO2)5/Bi:YIG/fused quartz) MPC increases almost six-fold as compared to the

case of a solitary Bi:YIG film with a thickness equal to the total thickness of all Bi:YIG layers of the photonic crystal. This occurs due to an increase in the effective opti