title: Enhanced optical magnetoelectric effect in a patterned polar ferrimagnet.
abstract: A simple method to dramatically enhance the optical magnetoelectric (ME) effect, i.e., nonreciprocal directional birefringence, is proposed and demonstrated for a polar ferrimagnet GaFeO3 as a typical example. We patterned a simple grating with a period of 4 microm on a surface of GaFeO3 crystal and used the diffracted light as a probe. The optical ME modulation signal for the Bragg spot of the order n=1 becomes gigantic in the photon energy 1-4 eV and reaches 1-2% of the bare diffracted light intensity in a magnetic field of 500 Oe. This is amplified by more than 3 orders of magnitude compared to that for the reflection of bulk GaFeO3. Fabricating a photonic crystal will make it possible to lead the way for the practical use of the optical ME effect.
authors.affiliation: Spin Superstructure Project (SSS), ERATO, Japan Science and Technology Agency (JST), c/o National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba Central 4, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8562, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Kida
authors.forename: Y
authors.initials: Y
authors.lastname: Kaneko
authors.forename: J P
authors.initials: JP
authors.lastname: He
authors.forename: M
authors.initials: M
authors.lastname: Matsubara
authors.forename: H
authors.initials: H
authors.lastname: Sato
authors.forename: T
authors.initials: T
authors.lastname: Arima
authors.forename: H
authors.initials: H
authors.lastname: Akoh
authors.forename: Y
authors.initials: Y
authors.lastname: Tokura