Electronics and Telecommunications Research Institute

Mi-Ran Park

O-Kyun Kwon

Hyun Soo Kim

Jong Sool Jeong

Byungseok Choi

Byung-Seok Choi

Dae Kon Oh

Kisoo Kim

Dong-Hun Lee

Gyung-Ock Kim

Yong-Hwan Kwon

Bongki Mheen

Young Tak Han

Jae-Sik Sim

Jeong-Woo Park

Byunseok Choi

Jong-Bum You

Disclosed is a multi-channel receiver optical sub assembly. The a multi-channel receiver optical sub assembly includes: a multi-channel PD array, in which a plurality of photodiodes (PDs) disposed on a first capacitor, and including receiving areas disposed at centers thereof and anode electrode pads arranged in an opposite direction at an angle of 180 degrees based on the receiving areas between the adjacent PDs is monolithically integrated; a plurality of transimpedance amplifiers (TIAs) arranged on a plurality of second capacitors, respectively, and connected with the anode pads of the respective PDs through wire bonding; a submount on which the first capacitor.

Multi-channel receiver optical sub assembly

Provided is a reflective colorless optical transmitter receiving a carrier signal, which is a continuous wave, and outputting a modulated optical signal. The reflective colorless optical transmitter includes a semiconductor optical amplifier (SOA) amplifying an input optical signal allowing the input optical signal to have a gain, an optical modulator connected to the SOA and outputting a modulated optical signal, a high reflectivity facet reflecting the modulated optical signal from the optical modulator, and a Bragg reflection mirror connected to the high reflectivity facet, the optical modulator, and the SOA in series, wherein a Bragg resonator is formed by the Bragg reflecting mirror and the high reflectivity facet.

Reflective colorless optical transmitter

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.

Optical waveguide platform with hybrid-integrated optical transmission device and optical active device and method of manufacturing the same

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.

Avalanche photodiodes and methods of fabricating the same

The present disclosure relates to an optical line terminal, the disclosure includes: an optical transmitter for generating a low speed downstream optical signal; a wavelength-multiplexer for wavelength-multiplexing the downstream optical signal; a first optical power branching tap coupler for allowing wavelength-multiplexed downstream optical signal to branch off; a wavelength band separator/coupler for separating between the wavelength-multiplexed downstream optical signal and a wavelength-multiplexed upstream optical signal; a circulation type wavelength-demultiplexer for wavelength-demultiplexing a downstream optical signal branched off by the first optical power branching tap coupler and an upstream optical signal separated by the wavelength band separator/coupler; an optical receiver for outputting a downstream electrical signal by using the wavelength-demultiplexed optical signal; and a signal processing module for controlling an optical power and a wavelength of the optical transmitter according to a strength of the downstream electrical signal.

Optical line terminal for bidirectional wavelength-division-multiplexing optical network

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.

Multi-channel optical receiving module

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.

Optical line terminal for monitoring and controlling upstream/downstream optical signals

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 receiving the wavelength-demultiplexed downstream WDM optical signal.

Wavelength-shifted bidirectional wavelength division multiplexing optical network

Avalanche photodiodes having accurate and reproductible amplification layer

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.

Tunable laser module

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 &#x3bc;m to about 0.5 &#x3bc;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.

Semiconductor integrated circuits including optoelectronic device for changing optical phase

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.

Methods of forming a compound semiconductor device including a diffusion region

Provided is a vertical cavity surface emitting device. The surface emitting device includes a lower mirror layer emitting light having a long wavelength, an active layer providing an optical gain, a tunnel junction layer for confining a current, and an upper mirror layer, which are sequentially stacked on a compound semiconductor substrate, wherein a heat release layer is formed on side surfaces of at least one of the active layer, the tunnel junction layer and the upper mirror layer by using etching process, and the heat release layer has greater thermal conductivity than at least one of the active layer, the tunnel junction layer and the upper mirror layer.

Growing community of inventors

Daejeon, South Korea

Mi-Ran Park