Electronics and Telecommunications Research Institute

Korea Telecommunication Authority

Kwang-Ryong Oh

Hyun-Soo Kim

Su Hwan Oh

Yongsoon Baek

Jong-Hoi Kim

Sahnggi Park

Kang-Ho Kim

Oh-Kee Kwon

Kyung-Hyun Park

Sung-Bock Kim

Hong-Man Kim

Jeong-Soo Kim

Yong-Soon Baek

Yong-Tak Lee

Chong-Dae Park

Jonghoi Kim

Eun-Deok Sim

Jung-ho Song

Sung-bock Kim

Moon-Ho Park

Ki-Sung Park

Ju-Heon Ahn

Kyung-hyun Park

Provided are a reflective semiconductor optical amplifier (R-SOA) and a superluminescent diode (SLD). The R-SOA includes: a substrate; an optical waveguide including a lower clad layer, an active layer independent of the polarization of light, and an upper clad layer sequentially stacked on the substrate, the optical waveguide comprising linear, curved, and tapered waveguide areas; and a current blocking layer formed around the optical waveguide to block a flow of current out of the active layer, wherein the linear and curved waveguide areas have a single buried hetero (BH) structure, and the tapered waveguide area has a dual BH structure.

Reflective semiconductor optical amplifier (R-SOA) and superluminescent diode (SLD)

Reflective semiconductor optical amplifier (R-SOA) with dual buried heterostructure

An optical modulator using a dynamic single mode laser diode (DSM-LD) integrated with a deflector is disclosed. The optical modulator for coupling a light beam to an optical fiber, the optical modulator includes: a laser diode for generating the light beam; and a deflector for deflecting a direction of the light beam according to an electric signal externally applied and outputting the defected light beam to the optical fiber, wherein the laser diode and the deflector are integrated with a multi-layer semiconductor structure in such a way that the light beam is modulated by changing a defection angle of the deflector.

Apparatus for modulating signal by using deflector integrated with dynamic single mode laser diode

Disclosed is a high speed optical signal processor which includes a saturable absorber area including a substrate, an active layer, a clad layer and a first upper electrode which are sequentially formed on one face of the substrate, and a first lower electrode formed on the other face of the substrate; and a gain-clamped optical amplifier area including a substrate having a diffraction grating for generating a laser beam, an active layer, a clad layer and a second upper electrode which are sequentially formed on one face of the substrate, and a second lower electrode formed on the other face of the substrate, the second upper electrode being isolated from the first upper electrode of the saturable absorber area.

High speed optical signal processor including saturable absorber and gain-clamped optical amplifier

A semiconductor optical device with a differential grating formed by a holography method and a method for manufacturing the same are provided. The provided semiconductor optical device includes an n-type InP substrate, a stack structure on the InP substrate having a waveguide and active layers, a first grating formed under the stack structure and on the InP substrate, and a second grating formed on the stack structure. The provided method for manufacturing the semiconductor optical device forms a first grating on the n-type InP substrate and under the active layer, and forms a second grating on the active layer. The first and second gratings are formed by the holography method.

Semiconductor optical devices with differential grating structure and method for manufacturing the same

Disclosed is a method for the fabrication of a spot-size converter with a lateral-tapered waveguide (or an active layer), which utilizes a mask during a lithographic process wherein the mask has a pad that can absorb strain to be occurred during forming a lateral-tapered waveguide pattern at its distal end and the lateral-tapered waveguide is fabricated by forming the distal end on the order of about 0.6 &mgr;m in width followed by forming the lateral-tapered waveguide on the order of 0.1 &mgr;m using an wet etching. Thus, it is possible to reduce a fabrication cost because it is free from a high-resolution electron beam lithography and a stepper, and hence enhance a reproducibility of the lateral-tapered waveguide because it is free from an excessive wet etching during the use of a contact exposure equipment. Further, it is possible to integrate the spot-size converter fabricated by the above with an optical device, resulting in an increased position adjustment and reproducibility of the spot-size converter, which in turn, leads to increase in yield for the optical device.

Method for manufacturing an optical device

Disclosed is a method for fabricating an optical integrated circuit capable of obtaining a current confinement and a maximum opto-coupling efficiency by using a simple process, in a case where an active device such as an optical waveguide and an optical amplifier. The method comprises a step for growing layers constituting the optical device over an InP substrate, a step for etching the grown layers by use of a wet etching method or a dry etching method of RIE along a plane perpendicular to a (001) plane, and a step for growing a core layer and a clad layer of the waveguide to be optically connected by use of a molecular organic chemical vapor deposition.

Method for fabricating an optical integrated circuit

Disclosed is an optical switch device for totally reflecting an incident light therein in accordance with a change in refractive index occurring owing to current application, which is manufactured by the steps of: sequentially forming an optical waveguide layer, an n-InP clad layer and an n-InGaAs cap layer on a main surface of an n-InP substrate using an epitaxial growing; selectively etching the n-InGaAs cap layer to form an opening tapered downward; diffusing an impurity into the n-InP clad layer through the opening and into the n-InGaAs cap layer to a predetermined depth from a surface thereof so as to form a first impurity diffused region in the n-InP clad layer under the opening and to form a second impurity diffused region along the surface of the n-InGaAs cap layer; etching the layers on the optical waveguide layer using a mask to form a ridge-shaped waveguide; and forming electrodes on the n-InGaAs cap layer and an exposed surface of the n-InP clad layer and on a surface which is opposite to the main surface of the n-InP substrate. Also, before forming the n-InGaAs cap layer, a p-InP current blocking layer is formed between the n-InP clad layer and the n-InGaAs cap layer so as to prevent a current from being dispersed other portions excluding the impurity diffused portion.

Optical Switching device

The present invention relates to an integrated photoelectric receiving device in which a PIN-type photodetector and a junction field effect transistor (FET) are integrated in a single chip. The photoelectric receiving device comprises a photodetector having a n-channel layer, an etching stopper layer and an absorption layer formed on a semi-dielectric substrate, the n-channel layer, the etching stopper layer and the absorption layer being formed in a reverse mesa shape and the substrate being etched by a predetermined depth; a transistor having a n-channel layer, an etching stopper layer and a p-type InP layer sequentially formed on the non-etched portion of the semi-insulator substrate, the p-type InP layer having an absorption layer formed thereon in a reversedmesa shape. Also, the invention contemplates a method of manufacturing the device.

Method of manufacturing an integrated photoelectric receiving device

Growing community of inventors

Daejeon, South Korea

Kwang-Ryong Oh