Abstract: An optical alignment device according to an embodiment of the inventive concept includes an optical alignment plate having a first hole and at least one second hole, in which the first hole and the second hole pass through the optical alignment plate, and an optical detection element disposed on the optical alignment plate. Here, the optical detection element includes a substrate having a first surface and a second surface, which face each other, a lens disposed on the first surface, and an optical sensor disposed on the second surface, and the optical detection element vertically overlaps the first hole and the second hole. The lens is exposed to the outside by the first hole, and the second hole is connected with a vacuum suction unit to fix the optical detection element to the optical alignment plate.

Abstract: Disclosed are a Mach-Zehnder interferometric optical modulator and a method for manufacturing the same. The modulator includes first and second lower clad layers, a core layer, an upper clad layer, a waveguide, and electrodes. The waveguide may include an input waveguide, a waveguide divider, branch waveguides, and a waveguide combiner. Each of the branch waveguides includes first and second connection regions connected to the waveguide combiner and the waveguide divider, respectively, and a phase shift region having a cross-section of a reverse mesa structure that has an upper width that is the same as widths of the first and second connection regions and a lower width that is smaller than the widths of the first and second connection regions.

Abstract: An optical alignment device according to an embodiment of the inventive concept includes an optical alignment plate having a first hole and at least one second hole, in which the first hole and the second hole pass through the optical alignment plate, and an optical detection element disposed on the optical alignment plate. Here, the optical detection element includes a substrate having a first surface and a second surface, which face each other, a lens disposed on the first surface, and an optical sensor disposed on the second surface, and the optical detection element vertically overlaps the first hole and the second hole. The lens is exposed to the outside by the first hole, and the second hole is connected with a vacuum suction unit to fix the optical detection element to the optical alignment plate.

Abstract: Disclosed are a Mach-Zehnder interferometric optical modulator and a method for manufacturing the same. The modulator includes first and second lower clad layers, a core layer, an upper clad layer, a waveguide, and electrodes. The waveguide may include an input waveguide, a waveguide divider, branch waveguides, and a waveguide combiner. Each of the branch waveguides includes first and second connection regions connected to the waveguide combiner and the waveguide divider, respectively, and a phase shift region having a cross-section of a reverse mesa structure that has an upper width that is the same as widths of the first and second connection regions and a lower width that is smaller than the widths of the first and second connection regions.

Abstract: Provided is a waveguide photodetector including a semiconductor substrate, a first optical waveguide and a second optical waveguide, which are sequentially laminated on the semiconductor substrate, in which each of the first optical waveguide and the second optical waveguide includes a first portion and a second portion, and the first portion extends from the second portion in a first direction parallel to a top surface of the semiconductor substrate, a refractive index matching layer disposed on the second portion of the second optical waveguide, a clad layer disposed on the refractive index matching layer, and an absorber disposed between the refractive index matching layer and the clad layer. Here, the second optical waveguide has a first conductive-type, the clad layer has a second conductive-type opposite to the first conductive-type, and the refractive index matching layer includes a first semiconductor layer that is an intrinsic semiconductor layer.

Abstract: Provided is a waveguide photodetector including a semiconductor substrate, a first optical waveguide and a second optical waveguide, which are sequentially laminated on the semiconductor substrate, in which each of the first optical waveguide and the second optical waveguide includes a first portion and a second portion, and the first portion extends from the second portion in a first direction parallel to a top surface of the semiconductor substrate, a refractive index matching layer disposed on the second portion of the second optical waveguide, a clad layer disposed on the refractive index matching layer, and an absorber disposed between the refractive index matching layer and the clad layer. Here, the second optical waveguide has a first conductive-type, the clad layer has a second conductive-type opposite to the first conductive-type, and the refractive index matching layer includes a first semiconductor layer that is an intrinsic semiconductor layer.

Abstract: An optical waveguide structure includes a substrate and a core structure disposed on the substrate. The substrate includes a first waveguide region, a second waveguide region, and a transition region between the first waveguide region and the second waveguide region. The core structure includes first core segments arranged in a first direction and a second direction crossing the first direction on the transition region. The core structure includes second core segments arranged in the first direction and the second direction on the second waveguide region. The first direction and the second direction are parallel to a top surface of the substrate.

Abstract: An optical waveguide structure includes a substrate and a core structure disposed on the substrate. The substrate includes a first waveguide region, a second waveguide region, and a transition region between the first waveguide region and the second waveguide region. The core structure includes first core segments arranged in a first direction and a second direction crossing the first direction on the transition region. The core structure includes second core segments arranged in the first direction and the second direction on the second waveguide region. The first direction and the second direction are parallel to a top surface of the substrate.

Abstract: An apparatus for purifying waste gases for an integrated semiconductor is provided, which includes a cover including a burner mounted thereon to generate a flame and a plurality of waste gas inlet pipes formed on a circumference of the burner to make waste gases flow therethrough; a reactor including upper and lower openings formed thereon so that the cover is detachably coupled to the upper opening, a converging member tapered to have a smaller diameter as going toward a lower portion thereof, and a transport pipe vertically arranged to communicate with an apex of the converging member, in which a water curtain is formed to prevent accumulation of by-products, to burn and discharge the inflow waste gases; and a cleaning portion integrally formed in the reactor to water-clean the burnt waste gases that are discharged into the reactor after passing through the transport pipe to collect particles. Since the burner, the reactor, and the scrubber are integrally formed in a body.

Abstract: There is provided a method for manufacturing a Mach-Zehnder electrooptic modulator including forming an intrinsic semiconductor layer including a Group III-V compound semiconductor on a Group III-V compound semiconductor substrate having an active region and a passive region, doping a first impurity in the intrinsic semiconductor layer corresponding to the active region to form a core layer disposed on the substrate and undoped with the first impurity and an upper clad layer disposed on the core layer and including a region doped with the first impurity, and patterning the core layer and the upper clad layer.

Abstract: An apparatus for purifying waste gases for an integrated semiconductor is provided, which includes a cover including a burner mounted thereon to generate a flame and a plurality of waste gas inlet pipes formed on a circumference of the burner to make waste gases flow therethrough; a reactor including upper and lower openings formed thereon so that the cover is detachably coupled to the upper opening, a converging member tapered to have a smaller diameter as going toward a lower portion thereof, and a transport pipe vertically arranged to communicate with an apex of the converging member, in which a water curtain is formed to prevent accumulation of by-products, to burn and discharge the inflow waste gases; and a cleaning portion integrally formed in the reactor to water-clean the burnt waste gases that are discharged into the reactor after passing through the transport pipe to collect particles. Since the burner, the reactor, and the scrubber are integrally formed in a body.

Abstract: A multiple electronic control unit (ECU) diagnosing system and a method thereof for a vehicle by which a diagnosis time for an ECU can be shortened by using an Ethernet protocol and a communication gateway. The multiple ECU diagnosing system for the vehicle applies a multiple ECU diagnosing algorithm of a one-to-n method which is more efficient than a diagnosis algorithm of a one-to-one method between diagnostic equipment. ECUs for the vehicle are connected through various communication networks (K-Line, CAN, LIN, FlexRay, and MOST) by using a communication gateway transferring messages and signals between the ECUs, thus significantly shortening a diagnosis time for the ECUs and acquiring a large amount of diagnosis information at the same time.

Abstract: Disclosed are a method and an apparatus for transmitting and receiving coherent optical OFDM.

Abstract: Provided is an apparatus and method for measuring IQ imbalance, and in particular, is an apparatus and method for measuring IQ imbalance for an optical receiver. The apparatus for measuring IQ imbalance for an optical receiver includes a light generating unit generating optical and reference signals to provide the optical and reference signals to an optical receiver, a graph creating unit creating a Lissajous figure by using an in-phase (I) signal and a quadrature-phase (Q) signal output from the optical receiver in response to the optical and reference signals, and a calculating unit calculating IQ imbalance for the optical receiver with reference to the Lissajous figure.

Abstract: Provided is a method of measuring signal transmission time difference of a measuring device. The measuring device according to embodiments, by measuring a skew on two optical paths through signal delays of sufficient sizes for skew measurement on the optical paths, even a skew having a minute size can be measured within a measurable range.

Abstract: An apparatus for measuring performance of a coherent optical receiver includes a beam splitter splitting light into first and second paths, a first optical modulator modulating the first path light, a variable optical attenuator controlling an optical power of the first optical modulator, a first polarization controller transmitting a signal controlling polarization of an output of the variable optical attenuator to the coherent optical receiver, a second optical modulator modulating the second path light, a variable optical delay line delaying time of an output of the second optical modulator, a second polarization controller transmitting a signal controlling polarization of an output of the variable optical delay line to the coherent optical receiver, a network analyzer measuring performance of the coherent optical receiver and controlling the optical modulators, and a controller transmitting a control signal to the optical modulators.

Abstract: A multiple electronic control unit (ECU) diagnosing system and a method thereof for a vehicle by which a diagnosis time for an ECU can be shortened by using an Ethernet protocol and a communication gateway. The multiple ECU diagnosing system for the vehicle applies a multiple ECU diagnosing algorithm of a one-to-n method which is more efficient than a diagnosis algorithm of a one-to-one method between diagnostic equipment. ECUs for the vehicle are connected through various communication networks (K-Line, CAN, LIN, FlexRay, and MOST) by using a communication gateway transferring messages and signals between the ECUs, thus significantly shortening a diagnosis time for the ECUs and acquiring a large amount of diagnosis information at the same time.

Abstract: Provided is a method of measuring signal transmission time difference of a measuring device. The measuring device according to embodiments, by measuring a skew on two optical paths through signal delays of sufficient sizes for skew measurement on the optical paths, even a skew having a minute size can be measured within a measureable range.

Abstract: Provided is an apparatus and method for measuring IQ imbalance, and in particular, is an apparatus and method for measuring IQ imbalance for an optical receiver. The apparatus for measuring IQ imbalance for an optical receiver includes a light generating unit generating optical and reference signals to provide the optical and reference signals to an optical receiver, a graph creating unit creating a Lissajous figure by using an in-phase (I) signal and a quadrature-phase (Q) signal output from the optical receiver in response to the optical and reference signals, and a calculating unit calculating IQ imbalance for the optical receiver with reference to the Lissajous figure.

Abstract: Provided is an electro-optic modulating device. The electro-optic modulating device includes an optical waveguide with a vertical structure and sidewalls of the vertical structure are used to configure a junction.