Electronics and Telecommunications Research Institute

Jong Sool Jeong

Hyun Soo Kim

O-Kyun Kwon

Mi-Ran Park

Byungseok Choi

O Kyun Kwon

Dong Hun Lee

Ki Soo Kim

Byung Seok Choi

Mi Ran Park

Kisoo Kim

Kwang Ryong Oh

Yong Soon Baek

Byung-Seok Choi

Dae Kon Oh

Young Tak Han

Dong Churl Kim

Ki Hong Yoon

Byunseok Choi

Provided herein is a wavelength/bandwidth tunable optical filter capable of flexibly tuning a wavelength and bandwidth, the wavelength/bandwidth tunable optical filter including an optical circulator configured to receive a WDM (Wavelength-Division-Multiplexing) optical signal from an optical cable; and a plurality of wavelength-tunable optical filters configured to receive the WDM optical signal via the optical circulator, wherein the plurality of wavelength-tunable optical filters reflect wavelengths of different bandwidths from one another.

Wavelength/bandwidth tunable optical filter and driving method thereof

An optical signal processing apparatus using a planar lightwave circuit (PLC) with a waveguide-array structure includes a PLC board including a waveguide-array structure, a cylinder lens for collimating optical signals emitted and output from the PLC board into parallel beams, a condenser lens for condensing, for each channel, optical signals output by passing through the cylinder lens, and a light receiving element for receiving optical signals condensed on at least one channel from the condenser lens and converting the optical signals into electrical signals, wherein the PLC board divides an optical signal input thereto into a plurality of different optical signals and outputs the optical signals at different propagation angles.

Optical signal processing apparatus using planar lightwave circuit with waveguide-array structure

Disclosed is an optical source device. The optical source device includes: a mode converter configured to be optically coupled with an optical fiber; a semiconductor optical amplifier coupled with the mode converter, and configured to amplify an optical signal input through the optical fiber; and an electro absorption modulator coupled to the optical amplifier, and configured to modulate the amplified optical signal and output the modulated optical signal, in which each of the semiconductor optical amplifier and the optical absorption modulator includes a heater.

Reflective optical source device

Disclosed are a method and an apparatus for selecting a wavelength by a wavelength tunable optical receiver. The method of selecting a wavelength of a wavelength tunable optical receiver includes: receiving, by the wavelength tunable optical receiver, an optical signal from a wavelength tunable optical transmitter; filtering, by the wavelength tunable optical receiver, the optical signal through a low frequency band electrical signal filter, and obtaining a low frequency signal; determining, by the wavelength tunable optical receiver, whether the low frequency signal is a valid signal based on a current value of the low frequency signal; and when the low frequency signal is the valid signal, obtaining, by the wavelength tunable optical receiver, an enable condition of a wavelength tunable optical filter through which the low frequency signal is selected, in which the low frequency signal includes a control/monitoring signal.

Method and apparatus for selecting wavelength by wavelength tunable optical receiver

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

Disclosed is a wavelength tunable laser apparatus, including: a first substrate configured to reflect inflow laser light, and tune a wavelength of the reflected laser light; and a second substrate configured to adjust a gain of the laser light input from the first substrate, reflect a specific wavelength of the laser light, and adjust a phase of oscillated laser light, in which the first substrate and the second substrate are formed in a single package form.

Coherent wavelength tunable laser apparatus

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

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

A semiconductor optical device includes a first mode converting core, a light amplification core, a second mode converting core, and a light modulation core disposed in a first mode converting region, a light amplification region, a second mode converting region, and a light modulating region of a semiconductor substrate, respectively, and a current blocking section covering at least sidewalls and a top surface of the light amplification core. The first mode converting core, the light amplification core, the second mode converting core, and the light modulation core are arranged along one direction in the order named, and are connected to each other in butt joints. The current blocking section includes first, second, and third cladding patterns sequentially stacked. The second cladding pattern is doped with dopants of a first conductivity type, and the first and third cladding patterns are doped with dopants of a second conductivity type.

Semiconductor optical devices and methods of fabricating the same

The present invention relates to a spot size converter and a method of fabricating the same, which provides efficient coupling between an optical fiber and integrated devices of optical waveguide. The spot size converter has an input and output optical waveguides formed in a vertical double-layer structure. Integrated to the output optical waveguide, an unidirectional side-tapered optical waveguide is formed. Due to the tapered structure of the optical waveguide, the effective refective index gradually changes along the length of the waveguide. Thus, the spot size of the optical signal gradually changes while the optical signal travels within the tapered optical waveguide. Therefore, the present invention effectively eliminates or minimizes the coupling loss and the reflection loss between the optical fiber and the devices connected to the spot size converter. In particular, the present invention provides method for easily fabricating a tapered and narrow optical waveguide structure using low-resolution photolithography technique and reducing the manufacturing cost and increasing the manufacturing yield at the same time.

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Daejeon, South Korea

Jong Sool Jeong