Electronics and Telecommunications Research Institute

Dong Woo Suh

Mun Cheol Paek

Ho Jun Ryu

Yong Woo Park

Hyeon Bong Pyo

Hojun Ryu

Yeung Joon Sohn

Yongwoo Park

Yeungjoon Sohn

Sang Hoon Kim

Kwang Yong Kang

Hyeon-Bong Pyo

Bongki Mheen

Jin-Yeong Kang

Gyung Ock Kim

Seok-bong Hyun

Mun-Cheol Paek

Ji Ho Joo

Hee Sook Chung

A method of growing a germanium (Ge) epitaxial thin film having negative photoconductance characteristics and a photodiode using the same are provided. The method of growing the germanium (Ge) epitaxial thin film includes growing a germanium (Ge) thin film on a silicon substrate at a low temperature, raising the temperature to grow the germanium (Ge) thin film, and growing the germanium (Ge) thin film at a high temperature, wherein each stage of growth is performed using reduced pressure chemical vapor deposition (RPCVD). The three-stage growth method enables formation of a germanium (Ge) epitaxial thin film characterized by alleviated stress on a substrate, a lowered penetrating dislocation density, and reduced surface roughness.

Growth of germanium epitaxial thin film with negative photoconductance characteristics and photodiode using the same

A leaky plasmon mode directional coupler and a polarization detection module for a magneto-optical pickup head, which uses the leaky plasmon mode directional coupler, are provided. The leaky plasmon mode directional coupler is manufactured by integrating a planar waveguide and a leaky plasmon mode waveguide, which share a cladding layer with each other, into one body. The polarization detection module includes the leaky plasmon mode directional coupler, a first photo diode, which is formed on the leaky plasmon mode directional coupler, and a second photo diode, which is located at an output port of the planar waveguide.

Leaky surface-plasmon mode directional coupler and polarization detection module for magneto-optical pickup head using the same

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.

Recording layer of magneto-optical storage medium having sublayer and method of fabricating the same

Provided is a focusing waveguide grating coupler using a leaky mode which can form single output beam while relieving the dependency on manufacturing processes. The focusing waveguide grating coupler of the present research includes: a substrate having a first refraction index n1; a first core layer having a second refraction index n2, the first core layer being formed on the substrate; a second core layer having a third refraction index n3, the second core layer being formed on the first core layer apart from the first core layer with a space d in between; a first cladding layer having a fourth refraction index n4, the first cladding layer being formed on the second core layer; a second cladding layer having a fifth refraction index n5, the second cladding layer being formed on the first cladding layer and inserted between the first core layer and the second core layer; and a Fresnel lens positioned on the second cladding layer, wherein the refractive indexes satisfy conditions of n5&#x3e;(n2, n3)&#x3e;n1 and n5&#x3e;n4; and light inputted through the first and second core layers to the Fresnel lens as radiated leaky beam by a leaky mode formed according to the conditions, and the leaky beam forms an optical focus by performing single directional coupling.

Highly efficient focusing waveguide grating coupler using leaky mode

A method for arranging unit inductors of an inductor having metal wiring that can make a full use of self-inductance and mutual-inductance which are determined based on the proportion of the area of an unit inductor and the proportion of the overlapping area with another unit inductor, and an inductor adopting the unit inductor arranging method. The unit inductor arranging method, wherein the inductor includes a first unit inductor, a second inductor and a third inductor, and self-inductance magnitudes of the unit inductors are in the order of the self-inductance of the third inductor&#x3e;the self-inductance of the second inductor&#x3e;the self-inductance of the first inductor, includes the steps of: a) coupling one end of the second unit inductor is connected to one end of the first unit inductor and one end of the third unit inductor to the other end of the first unit inductor in order to arrange the first unit inductor between the second and third unit inductors of which mutual-inductance has the largest value in mutual-inductances between the unit inductors; b) coupling the second unit inductor to a first external terminal; and c) coupling the third unit inductor to a second external terminal.

Growing community of inventors

Daejeon, South Korea

Dong Woo Suh