Abstract:
Provided is a semiconductor optical device having a current-confined structure. The device includes a first semiconductor layer of a first conductivity type which is formed on a semiconductor substrate and includes one or more material layers, a second semiconductor layer which is formed on the first semiconductor layer and includes one or more material layers, and a third semiconductor layer of a second conductivity type which is formed on the second semiconductor layer and includes one or more material layers. One or more layers among the first semiconductor layer, the second semiconductor, and the third semiconductor layer have a mesa structure. A lateral portion of at least one of the material layers constituting the first semiconductor layer, the second semiconductor layer, and the third semiconductor layer is recessed, and the recess is partially or wholly filled with an oxide layer, a nitride layer or a combination of them. The semiconductor optical device having the current-confined region is mechanically reliable, highly thermally conductive, and commercially preferable and can be used in a wavelength range for optical communications.
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.
Abstract:
Provided are an avalanche photodiode and a method of fabricating the same. The method of fabricating the avalanche photodiode includes sequentially forming a compound semiconductor absorption layer, a compound semiconductor grading layer, a charge sheet layer, a compound semiconductor amplification layer, a selective wet etch layer, and a p-type conductive layer on an n-type substrate through a metal organic chemical vapor deposition process.
Abstract:
Provided is a wavelength division multiplexed-passive optical network (WDM-PON) apparatus. The WDM-PON includes an optical source unit, an optical mux, and a chirped Bragg grating. The optical source unit generates an optical signal. The optical mux receives the optical signal from the optical source unit through one end of the optical mux, multiplexes the optical signal, and outputs the multiplexed optical signal. The chirped Bragg grating is connected to the other end of the optical mux. The chirped Bragg grating again reflects the optical signal having passed the optical mux to re-input a certain portion of the optical signal into the optical mux and the optical source unit. The optical mux performs a spectrum slicing on the re-inputted optical signal and operates the optical source unit using a channel wavelength of the optical mux as a main oscillation wavelength.
Abstract:
Provided is a semiconductor and a method for forming the same. The method includes forming a buried insulating layer locally in a substrate. The substrate is etched to form an opening exposing the buried insulating layer, and a silicon pattern spaced in at least one direction from the substrate is formed on the buried insulating layer. A first insulating layer is formed to enclose the silicon pattern.
Abstract:
A waveguide structure is provided. The waveguide structure includes: a slot channel waveguide including first and second patterns, which are spaced apart from each other to define a slot; a first upper layer covering at least a portion of the slot channel waveguide; and a second upper layer covering the remaining portion of the slot channel waveguide. A thermo-optic coefficient (TOC) of the channel waveguide times a TOC of the second upper layer is a negative number.
Abstract:
Provided are an etching method for a multi-layered structure of semiconductors in groups III-V and a method of manufacturing a VCSEL using the etching method. According to the etching method, a stacked structure including a first semiconductor layer and a second semiconductor layer is exposed to a plasma of a mixture consisting of Cl2, Ar, CH4, and H2 to etch the stacked structure, so that a mirror layer of the VCSEL is formed. The first semiconductor layer is formed of a semiconductor in groups III-V and the second semiconductor layer is formed of a semiconductor in groups III-V, other than the semiconductor of the first semiconductor layer. At least part of a lower mirror layer, a lower electrode layer, an optical gain layer, an upper electrode layer, and an upper mirror layer is etched using one time of an etching process, so that a clean and smooth etched surface is obtained.
Abstract:
The present invention relates to a method of fabricating vertical-cavity surface emitting lasers being watched as a light source for long wavelength communication. The present invention includes forming a layer having a high resistance near the surface by implanting heavy ions such as silicon (Si), so that the minimum current injection diameter is made very smaller unlike implantation of a proton. Further, the present invention includes regrowing crystal so that current can flow the epi surface in parallel to significantly reduce the resistance up to the current injection part formed by silicon (Si) ions. Therefore, the present invention can not only effectively reduce the current injection diameter but also significantly reduce the resistance of a device to reduce generation of a heat. Further, the present invention can further improve dispersion of a heat using InP upon regrowth and thus improve the entire performance of the device.
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.