Abstract:
A multistage optical packet switching apparatus with self electro-optic-effect device is disclosed. The apparatus is formed with multistage structure using a plurality of symmetrical self electro-optic-effect devices, self-routing being performed by the control for a header part of optical packets after self-duplication and amplification for the input optical signal. The optical packet switching apparatus using a plurality of symmetrical self electro-optic-effect devices includes a front stage having first and second self electro-optic-effect devices interconnected and a back stage having third and fourth self electro-optic-effect devices interconnected, the 1.quadrature. multistage structure comprising the unit switching modules interconnected each comprising the front and the back stages, the self-duplication and amplification being performed in the front stage and the switching being performed in the back stage. The use of the apparatus is an optical exchange.
Abstract:
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.
Abstract:
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.
Abstract:
A single mode surface emitting laser and its manufacturing method are provided. The surface emitting laser which has a characteristic of single transverse mode radiation in the broad region using reflectivity distribution of a reflector layer with an antiguide clad is provided. The single mode surface emitting laser comprises an n-type semiconductor substrate having an n-type lower electrode and an antireflection film thereunder, a laser pillar formed on the semiconductor substrate, the laser pillar having a bottom DBR, an active layer and a top DBR, a control layer formed on said laser pillar, the control layer consisting of a compound semiconductor of which energy gap is larger than radiation wavelength, an antiguide clad layer covering an outer portion of the laser pillar including the control layer and has higher reflective index than those of the active layer or the top DBR forming the laser pillar, a top electrode formed on the antiguide clad layer and the control layer, and an insulation film between the antiguide clad layer and the top electrode.
Abstract:
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.
Abstract:
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.