Abstract: Disclosed is an optical line terminal for monitoring and controlling upstream and downstream optical signals, and more particularly, to an optical line terminal for monitoring and controlling upstream and downstream optical signals, which adds different low frequency monitoring signals to upstream and downstream wavelength division multiplexing optical signals in a bidirectional wavelength division multiplexing (WDM) optical network and senses and detects low frequency components of upstream and downstream optical signals to unite, monitor, and control optical outputs and wavelengths of the upstream and downstream wavelength division multiplexing optical signals into a single system.

Abstract: Disclosed is a wavelength-shifted bidirectional WDM optical network including: an optical line terminal including an optical line terminal (OLT) including a first optical transmitter transmitting a downstream WDM optical signal, a first high-density wavelength multiplexer/demultiplexer wavelength-multiplexing the downstream WDM optical signal or wavelength-demultiplexing a wavelength-multiplexed upstream WDM optical signal, and a first optical receiver receiving the wavelength-demultiplexed upstream WDM optical signal; a remote node (RN) including a second high-density wavelength multiplexer/demultiplexer shifting a center wavelength of the upstream WDM optical signal and wavelength-multiplexing the upstream WDM optical signal with the shifted center wavelength or wavelength-demultiplexing the wavelength-multiplexed downstream WDM optical signal; and multiple optical network units (ONUs) each including a second optical transmitter transmitting the upstream WDM optical signal and second optical receiver receiv

Abstract: A multi-channel optical receiving module includes a first substrate disposed on a bench, optical fibers disposed in grooves of the first substrate, a first lens disposed on the first substrate and collimating optical signals through the optical fibers, a second substrate disposed on the bench at a side of the first substrate, a light receiving device disposed on the second substrate, a second lens disposed over the light receiving device, a mirror reflecting the optical signals between the first lens and the second lens, and a block fixing the mirror. The block includes through-holes transmitting the optical signals between the first and second lenses without refraction of the optical signals.

Abstract: Provided is a wavelength division multiplexing (WDM) optical transmitting apparatus including first to n-th optical transmitters configured to output first to n-th optical signals having different wavelengths, respectively; a wavelength multiplexer configured to multiplex the first to n-th optical signals and generate an output optical signal; a tap coupler configured to receive the output optical signal and generate a controlling optical signal based on some of the output optical signal; a controlling photodetector configured to receive the controlling optical signal and output an optical current based on the controlling optical signal; and a controller configured to control each of the first to n-th optical transmitters based on the optical current, wherein the controller comprises a look-up table, sequentially detects driving conditions for the first to n-th optical transmitters, stores the detected driving conditions in the look-up table, and controls the first to n-th optical transmitters based on the de

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 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 are a use of chemically-crosslinkable, poly(organophosphazene)s for biomaterials, chemically-crosslinkable poly(organophosphazene)s with a physiologically active substance covalently-bonded thereto, a use thereof for biomaterials, and a process for preparing the same. The chemical crosslinkings can be made by UV irradiation, and/or a crosslinker, and/or an additive, and/or an enzyme, and/or a mixing of at least one polymer.

Abstract: Disclosed are an optical waveguide platform with integrated active transmission device and monitoring photodiode. The optical waveguide platform with hybrid integrated optical transmission device and optical active device includes an optical waveguide region formed by stacking a lower cladding layer, a core layer and an upper cladding layer on a substrate; a trench region formed by etching a portion of the optical waveguide region; and a spot expanding region formed on the core layer in the optical waveguide region, in which the optical transmission device is mounted in the trench region and the optical active device is flip-chip bonded to the spot expanding region. The monitoring photodiode is flip-chip bonded to the spot expanding region of the core layer of the optical waveguide, thereby monitoring output light including an optical coupling loss that occurs during flip-chip bonding.

Abstract: Provided is a tunable laser module emitting an optical signal having high speed, high power and wideband wavelength tuning. The tunable laser module includes a laser array configured to emit an optical signal having a plurality of different lasing wavelengths, a temperature controller configured to change a temperature of the laser array, and an optical integration device configured to modulate or amplify the optical signal at a side of the laser array opposing the temperature controller.

Abstract: Provided is a semiconductor integrated circuit. The semiconductor integrated circuit includes a semiconductor pattern disposed on a substrate and including an optical waveguide part and a pair of recessed portions. The optical waveguide part has a thickness ranging from about 0.05 ?m to about 0.5 ?m. The recessed portions are disposed on both sides of the optical waveguide part and have a thinner thickness than the optical waveguide part. A first doped region and a second doped region are disposed in the recessed portions, respectively. The first and second doped regions are doped with a first conductive type dopant and a second conductive type dopant, respectively. An intrinsic region is formed in at least the optical waveguide part to contact the first and second doped regions.

Abstract: Provided are a use of chemically-crosslinkable, poly(organophosphazene)s for biomaterials, chemically-crosslinkable poly(organophosphazene)s with a physiologically active substance covalently-bonded thereto, a use thereof for biomaterials, and a process for preparing the same. The chemical crosslinkings can be made by UV irradiation, and/or a crosslinker, and/or an additive, and/or an enzyme, and/or a mixing of at least one polymer.

Abstract: An image sensor with a shared photodiode is provided. The image sensor includes at least two unit pixels, each of which includes a photodiode, a diffusion region which gathers electrons from the photodiode, a transfer transistor which connects the photodiode with the diffusion region, and a readout circuit which reads out a signal from the diffusion region. Photodiodes of neighboring unit pixels are disposed symmetrically to be adjacent to one another to form a shared photodiode. The image sensor does not have a STI region which causes a dark current restricting its performance and does not require a basic minimum design factor (a distance or an area) related to a STI region. A region corresponding to a STI region may be used as a region of a photodiode or for additional pixel scaling. Therefore, a limitation in scaling of a photodiode is overcome, and pixel performance is improved in spite of pixel scaling.

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: A biodegradable and thermosensitive poly(organophosphazene) with a functional group, a preparation method thereof, and a use thereof for delivery of bioactive substances are provided.

Abstract: Provided is a method of forming a compound semiconductor device. In the method, a dopant element layer is formed on an undoped compound semiconductor layer. An annealing process is performed to diffuse dopants in the dopant element layer into the undoped compound semiconductor layer, thereby forming a dopant diffusion region. A rapid cooling process is performed using liquid nitrogen with respect to the substrate having the dopant diffusion region.

Abstract: Provided is a tunable laser module emitting an optical signal having high speed, high power and wideband wavelength tuning. The tunable laser module includes a laser array configured to emit an optical signal having a plurality of different lasing wavelengths, a temperature controller configured to change a temperature of the laser array, and an optical integration device configured to modulate or amplify the optical signal at a side of the laser array opposing the temperature controller.

Abstract: Provided is a semiconductor integrated circuit. The semiconductor integrated circuit includes a semiconductor pattern disposed on a substrate and including an optical waveguide part and a pair of recessed portions. The optical waveguide part has a thickness ranging from about 0.05 m to about 0.5 ?m. The recessed portions are disposed on both sides of the optical waveguide part and have a thinner thickness than the optical waveguide part. A first doped region and a second doped region are disposed in the recessed portions, respectively. The first and second doped regions are doped with a first conductive type dopant and a second conductive type dopant, respectively. An intrinsic region is formed in at least the optical waveguide part to contact the first and second doped regions.

Abstract: Provided are a vertical cavity surface emitting laser (VCSEL) module providing accurate alignment between a VCSEL and a monitoring photodiode (MPD) for efficiently detecting light emitted by the VCSEL and a method of fabricating the VCSEL module. The VCSEL module includes: a first mirror layer, a first semiconductor conducting layer, an active layer, a tunnel junction layer, and a second semiconductor conducting layer sequentially formed on a first region in a substrate having first and second regions; a MPD disposed on a portion of the second semiconductor conducting layer in the first region; and a VCSEL including layers having the same shapes as the first mirror layer, the first semiconductor conducting layer, the active layer, the tunnel junction layer and the second semiconductor conducting layer in the first region, and a second mirror layer formed on a portion of the second semiconductor conducting layer, and sequentially formed on the second region in the substrate.

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: Provided is a method of forming a compound semiconductor device. In the method, a dopant element layer is formed on an undoped compound semiconductor layer. An annealing process is performed to diffuse dopants in the dopant element layer into the undoped compound semiconductor layer, thereby forming a dopant diffusion region. A rapid cooling process is performed using liquid nitrogen with respect to the substrate having the dopant diffusion region.