National Institute of Advanced Industrial Science and Technology

Hidekazu Saito

Shinji Yuasa

Koji Ando

Vadym Zayets

An optical device having a plasmonic waveguide, in which the plasmonic waveguide has a layered structure of at least three layers that a ferromagnetic metal layer, a first dielectric layer, and a second dielectric layer are layered in this order, in which the first and second dielectric layers are layers that allow light to be transmitted therethrough, and in which a refractive index of the second dielectric layer is higher than a refractive index of the first dielectric layer; and an optical isolator, having the optical device.

Optical device using a plasmonic waveguide, and optical isolator

A nonvolatile optical memory element in which a ferromagnetic body is provided on a semiconductor causes such a problem that in a case where magnetization of the ferromagnetic body is read by light, magneto-optical response becomes very small when the ferromagnetic body is small in volume. The present invention provides a memory element, a memory device, and a data reading method, each of which is applicable to data reading from a nonvolatile optical memory element. In a nonvolatile optical memory element having a structure in which a ferromagnetic body is provided on a semiconductor that is connected to an optical waveguide, electrons are injected into the semiconductor via the ferromagnetic body so that the electrons that are spin-polarized according to a magnetization direction of the ferromagnetic body are injected into the semiconductor, thereby enlarging a region in which a photomagnetic effect occurs effectively. By applying an electric pulse and an optical pulse to the nonvolatile optical memory element, it is possible to effectively read recorded data according to a magnetization direction of the ferromagnetic body.

Growing community of inventors

Tsukuba, Japan

Hidekazu Saito