Electronics and Telecommunications Research Institute

Dae Kon Oh

Jin Soo Kim

Jin Hong Lee

Sung Ui Hong

Ho Sang Kwack

Hyun Soo Kim

Kisoo Kim

O-Kyun Kwon

Byung-Seok Choi

Byung Seok Choi

Dong Churl Kim

Sung Bock Kim

Mi-Ran Park

Joon Tae Ahn

Bong Je Park

Su Hwan Oh

Hong-Seok Seo

Won Seok Han

Ki Soo Kim

Yong-Hwan Kwon

Bongki Mheen

Jong Sool Jeong

Jae-Sik Sim

Kihong Yoon

Provided are a quantum dot laser diode and a method of manufacturing the same. The method of manufacturing a quantum dot laser diode includes the steps of: forming a grating structure layer including a plurality of gratings on a substrate; forming a first lattice-matched layer on the grating structure layer; forming at least one quantum dot layer having at least one quantum dot on the first lattice-matched layer; forming a second lattice-matched layer on the quantum dot layer; forming a cladding layer on the second lattice-matched layer; and forming an ohmic contact layer on the cladding layer. Consequently, it is possible to obtain high gain at a desired wavelength without affecting the uniformity of quantum dots, so that the characteristics of a laser diode can be improved.

Quantum dot laser diode and method of manufacturing the same

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

Provided are a semiconductor laser diode and a method of manufacturing the same. The semiconductor laser diode includes a lower cladding layer disposed on a substrate; a ridge including an optical waveguide layer, an active layer, an upper cladding layer, and an ohmic contact layer, which are sequentially stacked on the lower cladding layer, and having a predetermined width, which is obtained by performing a channel etching process on both sides of the ridge; an oxide layer disposed on surfaces of the upper and lower cladding layer to control the width of the ridge; a dielectric layer disposed on left and right channels of the ridge; an upper electrode layer disposed on the entire surface of the resultant structure to enclose the ridge and the dielectric layer; and a lower electrode layer disposed on a bottom surface of the substrate. The method is simpler than a conventional process of manufacturing a semiconductor laser diode. Also, by controlling a wet oxidation time, the width of a ridge can be freely controlled and an ohmic contact layer can be automatically formed.

Semiconductor laser diode and method of manufacturing the same

Provided is a double clad fiber device. The double clad fiber device includes a double clad fiber, a pump combiner, at least one first laser diode, and at least one second laser diode. The double clad fiber includes a core and a clad. The pump combiner provides pump light to the core and the clad through one end of the double clad fiber, respectively. The at least one first laser diode provides first pump light to the clad through the pump combiner. The at least one second laser diode provides second pump light to the core through the pump combiner.

Double clad fiber laser device

An optical amplifier includes a passive waveguide region and an active waveguide region. The passive waveguide region is configured to receive an incident optical signal and adjust a mode of the optical signal. The active waveguide region is integrated to the passive waveguide region and configured to perform gain modulation on the optical signal received from the passive waveguide region by changing density of carriers in response to a current applied to the active waveguide region. Internal loss of the active waveguide region is adjusted to produce a resonance effect and thereby to increase bandwidth of the active waveguide. Therefore, the optical amplifier can have a wide bandwidth under a low-current condition.

Optical amplifier

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 are a semiconductor optical amplifier and an optical signal processing method using the same. The reflective semiconductor optical amplifier includes: an optical signal amplification region operating to allow a downward optical signal incident from the external to obtain a gain; and an optical signal modulation region connected to the optical signal amplification region and generating a modulated optical signal. The downward optical signal is amplified through a cross gain modulation using the modulated optical signal and is outputted as an upward optical signal.

Reflective semiconductor optical amplifier and optical signal processing method using the same

Provided is an external cavity laser light source. The light source includes a substrate, an optical waveguide, and a current blocking layer. The optical waveguide includes a passive waveguide layer, a lower clad layer, an active layer, and an upper clad layer that are sequentially stacked on the substrate and is divided into regions including a linear active waveguide region, a bent active waveguide region, a tapered waveguide region, and a window region. The current blocking layer was formed an outside of the active layer to reduce leakage current. The linear and bent active waveguide regions have a buried heterostructure (BH), and the tapered waveguide region and the window region have a buried ridge stripe (BRS) structure. The passive waveguide layer a width substantially equal to a maximal width of the tapered waveguide region at least in the bent active waveguide region, the tapered waveguide region, and the window region.

External cavity laser light source

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 method of forming quantum dots, including: forming a buffer layer on an InP substrate so as to be lattice-matched with the InP substrate; and sequentially alternately depositing In(Ga)As layers and InAl(Ga)As or In(Ga, Al, As)P layers that are greatly lattice-mismatched with each other on the buffer layer so as to form In(Ga, Al)As or In(Ga, Al, P)As quantum dots.

Method for forming quantum dots by alternate growth process

Provided is a distributed feedback semiconductor laser structure including: a first clad layer; a first ridge waveguide formed on the first clad layer; an active layer formed on the first ridge waveguide; a second ridge waveguide formed on the active layer; a second clad layer formed on the second ridge waveguide; an ohmic contact layer formed on the second clad layer; and a plurality of gratings formed in at least one of the first and second clad layers, making a predetermined angle with the first ridge waveguide or the second ridge waveguide, and periodically arranged in a longitudinal direction of the first or second ridge waveguide. As a result, a general hologram lithography process capable of mass production is applied to the present invention so that process time can be reduced. Also, a distributed feedback semiconductor laser structure using a quantum-dot active layer that does not require an additional process for obtaining a pure single-wavelength is provided.

Semiconductor laser structure including quantum dot

A distributed feedback (DFB) quantum dot semiconductor laser structure is provided. The DFB quantum dot semi-conductor laser structure includes: a first clad layer formed on a lower electrode; an optical waveguide (WG) formed on the first clad layer; a grating structure layer formed on the optical WG and including a plurality of periodically disposed gratings; a first separate confinement hetero (SCH) layer formed on the grating structure layer; an active layer formed on the first SCH layer and including at least a quantum dot; a second SCH layer formed on the active layer; a second clad layer formed on the second SCH layer; an ohmic layer formed on the second clad layer; and an upper electrode formed on the ohmic layer. Accordingly, an optical WG is disposed on the opposite side of the active layer from the grating structure layer, thereby increasing single optical mode efficiency. And, an asymmetric multi-electrode structure is used for applying current, thereby maximizing purity and efficiency of the single mode semiconductor laser structure.

Distributed feedback (DFB) quantum dot laser structure

A DBR structure in a VCSEL diode, a method of manufacturing the DBR structure, and a VCSEL diode are provided. The DBR structure in the VCSEL diode includes: an InAlGaAs layer having a predetermined refractive index and disposed on an InP substrate; a first InAlAs layer having a lower refractive index than the InAlGaAs layer and disposed on the InAlGaAs layer; an InP layer having a lower refractive index than the InAlGaAs layer and disposed on the first InAlAs layer; and a second InAlAs layer having a lower refractive index than the InAlGaAs layer and disposed on the InP layer. Thus, the DBR structure can reduce optical loss due to type-II band line-up at a junction between the InAlGaAs layer and the InP layer, and thus improve device characteristics.

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Daejeon, South Korea

Dae Kon Oh