Electronics and Telecommunications Research Institute

Yong Woo Park

Mun Cheol Paek

Ho Jun Ryu

Dong Woo Suh

Hyeon Bong Pyo

Yeung Joon Sohn

Kwang Yong Kang

Hee Sook Chung

An optical head has a beam input/output coupler on a planar waveguide and other parts including: a light transmitting element emitting a beam; a planar waveguide formed on a substrate and receiving the beam oscillated from the light transmitting element; a beam input/output coupler integrated as a thin film on a portion of the planar waveguide and receiving the beam through the planar waveguide to transmit the beam vertically toward a disc positioned above the planar waveguide or transmitting the beam reflected from the disc through the planar waveguide; and light receiving elements receiving the beam propagated to the planar waveguide through the beam input/output coupler.

Optical head having a beam input/output coupler on a planar waveguide

Provided are a stamper fabricated by using an embossing master and a focusing grating coupler fabricated by using the stamper, which is applicable to a subminiature pickup head for a mobile optic disk, whereby it is possible to reduce a weight and a volume of the pickup head with a simple process and low cost and to apply for mass production.

Method of fabricating stamper and focusing grating coupler using the same

Provided is a planar focusing grating coupler, comprising: a light waveguide including a cladding layer and a core layer formed on a substrate and maintaining incident laser light in a single mode; and a focusing grating coupler formed to have a predetermined grating pitch at a certain area over the core layer, wherein the light using to the light waveguide forms a focal point with the grating layer in the direction perpendicular to the focusing grating coupler, whereby an ultra small pickup head for a mobile optical disk can be used.

Planar focusing grating coupler

A recording layer of a magneto-optical storage medium having a sublayer in accordance with the present invention comprises a recording layer on which information is recorded and stored; and a sublayer formed above or below the recording layer and made up of an alloy containing a transition metal, wherein a magnetic anisotropy energy of the sublayer is exchange-coupled to the recording layer, thereby enhancing a coercive force of the recording layer. The sublayer may be formed in a single-layered structure having one layer, or in a multi-layered structure having a plurality of layers. The sublayer is preferably made up of an alloy containing a transition metal used for the recording layer. According to the present invention, the coercive force of the recording layer can be increased by an exchange coupling effect between the recording layer and its adjacent sublayer, and thus, the stability of the magnetic domain in the recording layer can be improved. Therefore, the size of the magnetic domain can be significantly reduced, and the density of recording can be increased.

Growing community of inventors

Daejeon-Shi, South Korea

Yong Woo Park