Electronics and Telecommunications Research Institute

Kyung-Sook Hyun

O-Kyun Kwon

Kwang-Joon Kim

El-Hang Lee

Byueng-Su Yoo

Hyo-Hoon Park

Seok-Ho Song

Hye-Yong Chu

The present invention relates to a wavelength demultiplexer. More particularly, the present invention provides the wavelength demultiplexer with straight optical waveguide that minimizes the bending loss of optical waveguide caused in the wavelength demultiplexer. A wavelength demultiplexer with straight optical waveguide in accordance with the present invention comprises an optical power distributor, a plurality of optical waveguides, and an optical power combiner. The optical power distributor evenly divides multiplexed input light by intensity. The number of optical waveguide transmits the divided multiplexed light and causes constant optical path length differences among adjacent waveguides. The optical waveguide is straight optical waveguide and includes two parts of different effective refractive indices. The optical power combiner receives output signals of the plurality of optical waveguides and separates the output signals by phase.

Wavelength demultiplexer without waveguide bending loss

For a multiple transmission communication system, how to individually isolate the transmitted lights and then to distribute to the terminals has been primary concerns to be solved. In the photodetector structure, an absorption layer may be configured as either multiple quantum well structures corresponding to operational wavelengths, or filter-based structure, allowing to select wavelengths in a 1:2:4:8 ratio as an absorptance for each wavelength. In case of using such four-fold lights, the determination as to which wavelength among four-fold wavelengths can be made based upon the total amounts of the current flow in such a photodetector. The photodetector employing such schemes is provided from the present invention.

Photodetector for simultaneous recognition of multiple wavelengths, and

An improved parallel optical logic operator provides a path for light to pass through substrates in which a light source and an optical logic device are arranged. An optical logic device operates by transmission of light forwarded to a predetermined direction. This increases integration efficiency of the system by eliminating optical parts for changing the light path. A unit chip includes a laser array for generating a predetermined light in accordance with an electrical signal for a logic process, a laser array substrate on which via holes are formed for passing light, a microlens array for converting the light beam emitted from each laser device of the laser array into a parallel light beam for passing through the via hole, and an optical logic circuit array formed with a combination of an S-SEED which performs a logic function by transmission of the light signal through an optical window in S-SEED. A plurality of unit chips are laminated so that the light emitted from the laser device of one of the unit chips passes through an optical logic circuit of a corresponding unit chip and can be made incident on the optical logic circuit in the next unit chip through a via hole.

Compact optical logic operator array

A vertical modulator with a dual mode distributed Bragg reflection (DBR), includes a pair of integrated elements using different wavelengths to provide functions of logical operation, data switching and wavelength conversion. The optical device includes a first optical structure operating at a first wavelength (.lambda..sub.1) and a second optical structure operating at a second wavelength (.lambda..sub.2). The first and second optical structures are formed over a semiconductor substrate. The first optical structure, which operates at the first wavelength (.lambda..sub.1), transmits its data to the second optical structure so that data corresponding to the second wavelength (.lambda..sub.2) can be output. Since the wavelength of input light is different from the wavelength of output light, the optical device serves as a modulator which performs a logic operation and switching function while carrying out wavelength conversion.

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Daejeon, South Korea

Kyung-Sook Hyun