Electronics and Telecommunications Research Institute

University-industry Cooperation Group of Kyung Hee University

Wang-Joo Lee

Jae-Ick Choi

Jae-Myoung Lee

Kwang-Joon Kim

Je-Soo Ko

Dong-Ho Kim

Tae-Joon Park

Yong-Il Jun

Sung-hoon Kwak

Young-Boo Kim

Jeong-ho Ju

Bom-Son Lee

Tack-Gyu Kim

A metamaterial transmission line for transmitting an electromagnetic wave. The metamaterial transmission line may include a substrate including a substrate configured to include a an upper portion and a lower portion on which a ground plane is formed, a signal line configured to be formed on the substrate, and a defected ground structure configured to include an etched region and two metal portions, wherein the etched region is generated by etching a part of the ground plane and the metal portions extend from the signal line and are disposed on the etched region.

Metamaterial transmission line apparatus and method of implementing the same

Provided is a high power efficiency optical-wireless transmitter capable of solving problems of low power efficiency, signal distortion due to non-linearity of output, large number of connection terminals, and non-uniformity of optical power intensities of optical sources. The high power efficiency optical wireless transmitter includes: an amplitude-to-array coder converting an amplitude of an electric signal input from a baseband modulator into optical source control signals so as to generate an optical output power corresponding to the electric signal; optical source driver groups driving optical sources based on the optical source control signals of the amplitude-to-array coder; and MMRS (modified mixed radix system) or MMRR (modified mixed radix system with Redundancy) optical source group driven by the optical source driver groups to generate various optical power intensities.

High power efficiency optical-wireless transmitter

Disclosed are a projecting type hyper-lens and a method of manufacturing the same. The projecting type hyper-lens includes a main lens layer and a substrate layer. A front surface of the main lens layer is recessed. The substrate layer supports the main lens layer. A front central portion of the main lens layer protrudes beyond a surface of the substrate layer. The projecting type hyper-lens allows an object to move towards a front surface of the hyper-lens until a distance between the front surface of the hyper-lens and the object is smaller than a half-wavelength of light, and thus images an object smaller than a half-wavelength of used light. Evanescent waves scattered from an object is used in a manner convenient to a user.

Projecting type hyper-lens and method of manufacturing the same

The present invention relates to an apparatus and method for extracting an optical clock using filters and an amplifier. The object of the present invention is to provide an extraction of neighboring frequency components using wavelength fixed optical filters and an amplifier. In accordance with an aspect of the present invention, there is provided an apparatus for extracting an optical clock to extract a clock from the optical signal provided with plurality of peaks on a spectrum, including a first filter for extracting a central frequency component, a second filter for extracting a frequency component adjacent to the first frequency component, the amplifier for amplifying amplitude of the second frequency component until the amplitude of the second frequency component becomes the same as that of the first frequency component and the receiver for extracting a clock to do beating the first frequency component and the second frequency component.

Apparatus for extracting optical clock using filters and amplifier and method for the same

Provided are a method and an apparatus for detecting the fault of an optical switch. The apparatus includes an optical monitoring signal generator, a coupler, a splitter, a plurality of optical detecting and output power transition sensing units, and a fault determiner. The optical monitoring signal generator generates optical monitoring signals having different wavelengths from optical signals including data to be transmitted. The coupler optically couples the optical monitoring signals to the optical signals including data to be transmitted and inputs the coupled optical signals to an optical switch. The splitter splits the optical monitoring signals from optical signals output from the optical switch. The plurality of optical detecting and output power transition sensing units detect output power transitions of the split optical monitoring signals. The fault determiner receives information on setting the optical switch from an external source, compares the information with the detected output power transitions of the split optical monitoring signals, and determines whether the optical switch malfunctions depending on whether the information coincides with the detected output power transitions of the split optical monitoring signals.

Method and apparatus for detecting optical switch fault by monitoring optical output transitions

Growing community of inventors

Daejeon-si, South Korea

Wang-Joo Lee