Abstract: An orthogonal frequency division multiple access-passive optical network including a plurality of optical network units each configured to generate orthogonal frequency division multiplexed signals, which are allocated thereto, based on a central frequency for frequency division multiplexing that is allocated in advance, and to use the generated signals in upstream transmission.

Abstract: A method of fabricating an organic electroluminescent device (OELD) according to the present invention has steps of repairing a pixel region by irradiating a laser on a drain contact hole of a passivation layer in a pixel region in need of the repair; and disabling the connection between an organic electroluminescent diode and a drain electrode of a driving thin film transistor (TFT), where the pixel region of the OELD has i) the driving TFT comprising the drain electrode, ii) the passivation layer covering the driving TFT, while comprising the drain contact hole exposing the drain electrode of the driving TFT, and iii) the organic electroluminescent diode connected to the drain electrode of the driving TFT via the drain contact hole.

Abstract: In a wireless optical communication system in which communication is performed based on a free space and a plurality of the communication apparatuses are arranged in a ring form around a central office terminal (COT), the communication apparatus monitors optical signals received in a first direction or in a second direction opposite to the first direction, and selects a first path through which the optical signals in the first direction are received and a second path through which the optical signals in the second direction are received. The communication apparatus converts an optical signal having a predetermined unique wavelength from among the optical signals received through the selected path into a signal of a frequency domain having a plurality of subcarriers, and obtains packet data mapped to each of the subcarriers.

Abstract: An APC receptacle stub and an APC TOSA having the same are provided. The APC receptacle stub includes a first APC stub and a second APC stub. The first APC stub has an optical fiber inserted thereto and is provided with one end section polished in an APC shape. The second APC stub has an optical fiber inserted thereto and is provided with one end section polished in an APC shape and an opposite end section which is coupled to an opposite end section of the first APC stub through rotation adjustment in the same axial direction as an axial direction of the opposite end section of the first APC stub. The APC receptacle stub enables easy optical alignment and is applicable to a light source that is sensitive to reflection.

Abstract: An optical transmitter and an optical transceiver including the same are provided. The optical transmitter may include a semiconductor laser diode to output optical signals, a multilayer thin film filter to receive the optical signals and pass optical signals corresponding to a transmission wavelength band, and a concave lens to collect the optical signals passed through the multilayer thin film filter.

Abstract: Disclosed are an apparatus and method for detecting optical signals. The optical signal detection apparatus includes: a signal receiver to convert a received optical signal into an electrical signal; a threshold decision unit to establish a mathematical model based on the electrical signal and to decide an optimized threshold value based on the mathematical model; and a signal detector to detect the electrical signal based on the optimized threshold value. Hence, since threshold values optimized adaptively according to received signals are used, a bit error rate may be lowered and accordingly detection performance may be improved.

Abstract: In a Wavelength-Division-Multiplexed Passive Optical Network (WDM-PON) utilizing a conventional downstream optical signal reusing method, there is an inventory problem that different optical transmitter types need to be provided for the operation, management, replacement, etc. of a system. A WDM-PON system according to the present invention, includes: a seed light (SL) unit generating a seed light whose wavelength intervals and center wavelengths are adjusted using at least one seed light source; an optical line terminal (OLT) receiving the wavelength-multiplexed seed light from the seed light unit, transmitting a downstream optical signal to a subscriber of the WDM-PON, and receiving a upstream optical signal from the subscriber; and an optical network unit (ONU) receiving the downstream optical signal from the OLT, flattening and modulating the downstream optical signal with upstream data so that the downstream optical signal is reused for carrying upstream data.

Abstract: Provided is an external cavity laser using a multilayered thin film filter and an optical transmitter having the same. The external cavity laser may include a semiconductor laser diode to output an optical signal, a lens to cause the optical signal output from the semiconductor laser diode to converge, a multilayered thin film filter to receive the optical signal passed through the lens and to pass the optical signal in a bandpass wavelength range, and a partial reflector to transmit the optical signal transmitted through the multilayered thin film filter to an optical fiber.

Abstract: Disclosed is a cloud base station in an orthogonal frequency division multiplexing (OFDM)-based fixed-mobile converged access network and an operation method thereof. The cloud base station may include a physical (PHY) layer unit to perform a quadrature amplitude modulation (QAM) of a parallel signal received from a media access control (MAC) layer per subcarrier, and an optical orthogonal frequency division multiplexing (OFDM) transceiver to transform the QAM modulated subcarriers into a time domain to generate an OFDM sample per subcarrier, add a cyclic prefix (CP) and control information to for operating an enhanced radio unit (eRU) to the OFDM sample per subcarrier to generate a downstream signal, and transmit the downstream signal.

Abstract: An apparatus for driving a wavelength-independent light source is provided. The apparatus includes a seed light signal generation unit configured to generate seed light signals with one or more wavelengths based on a wavelength identification signal, a wavelength light detection unit configured to detect the wavelength identification signal from the seed light signals, an extraction unit configured to extract wavelength information corresponding to the detected wavelength identification signal and extract a driving condition of a wavelength-independent light source corresponding to the extracted wavelength information, and a driving unit configured to drive the wavelength-independent light source according to the extracted driving condition.

Abstract: The present disclosure provides a lighting apparatus using a light-emitting diode (LED), which includes: LEDs; a power transfer substrate with the LEDs thereon; a radiating member radiating heat generated in the LEDs; a driver electrically connected to the power transfer substrate and integrally coupled to the power transfer substrate and the radiating member; and a heat insulation layer reducing the amount of heat transferred from the radiating member to the driver. In addition, the present disclosure provides a lighting apparatus using an LED, which further includes a cradle fixed to a given object and detachably fixing a lighting body in which a power transfer substrate with LEDs thereon, a radiating member and a driver have been integrally coupled.

Abstract: A wavelength tunable light source includes: an optical gain medium generating light; a wavelength tunable filter positioned on a optical path and transmitting or reflecting only a predetermined wavelength generated from and injected into the optical gain medium; a first housing where the optical gain medium and the wavelength tunable filter are mounted; and an optical fiber block providing the optical wave having the predetermined wavelength come from the wavelength tunable filter, wherein the wavelength tunable filter comprised of a dielectric thin-film filter formed by alternately stacking a first dielectric thin film layer and a second dielectric thin film layer having different refractive index.

Abstract: The present disclosure discloses a lighting apparatus using a PN junction light-emitting element, the apparatus comprising: a power transmitting substrate; PN junction light-emitting elements mounted on the power transmitting substrate; circuit elements mounted on the power transmitting substrate and controlling power provided to the PN junction light-emitting elements; and a top cover covering the circuit elements and forward reflecting light emitted by the PN junction light-emitting elements.

Abstract: Provided are a user-selectable laser and an optical transmitter including the same. The user-selectable laser is an external cavity laser including a semiconductor laser diode for outputting an optical signal, and a wavelength selection filter. The user-selectable laser may allow a user to select a wavelength selection filter which is optically coupled with the semiconductor laser diode and selectively causes oscillation at the wavelength of an optical signal output from the semiconductor laser diode.

Abstract: Magnetostrictive transducers for monitoring wall thinning in a pipe, and an apparatus and method for monitoring wall thinning in a pipe using magnetostrictive transducers are provided. The magnetostrictive transducers generate broadband multimode shear horizontal (SH) waves, and allow the generated SH waves to travel along the pipe, thus correctly monitoring a status of the wall thinning of the pipe. The apparatus includes a transmitting transducer which is installed outside of a pipe and generates shear horizontal (SH) waves traveling along the pipe, a receiving transducer which is spaced apart from the transmitting transducer and measures the shear horizontal (SH) waves traveling along the pipe, and a controller for monitoring wall thinning of the pipe by exciting and measuring output signals of the transmitting and receiving transducers.

Abstract: A mobile terminal and panoramic photographing method for the same are provided. The panoramic photographing method includes displaying a preview image upon selection of a panoramic mode, successively capturing a first partial image and second partial image in response to input of a shooting start signal, setting a photographing direction through a comparison between the first partial image and second partial image, and producing a panoramic image in the set photographing direction. As a result, the user does not have to set the photographing direction to capture a panoramic image using a mobile terminal.

Abstract: A method and apparatus for controlling a reflective semiconductor optical amplifier (RSOA) are provided. The RSOA control apparatus sets a threshold current at which a light source starts to oscillate to be constant regardless of a wavelength of seed light by controlling a driving temperature for driving a RSOA, and adjusts an optical characteristic which is differently output for each wavelength of seed light to be constant by controlling a driving current.

Abstract: The present disclosure discloses a lighting apparatus using a PN junction light-emitting element, the apparatus comprising: a power transmitting substrate; PN junction light-emitting elements mounted on the power transmitting substrate; circuit elements mounted on the power transmitting substrate and controlling power provided to the PN junction light-emitting elements; and a top cover covering the circuit elements and forward reflecting light emitted by the PN junction light-emitting elements.

Abstract: An apparatus for driving a wavelength-independent light source is provided. The apparatus includes a seed light signal generation unit configured to generate seed light signals with one or more wavelengths based on a wavelength identification signal, a wavelength light detection unit configured to detect the wavelength identification signal from the seed light signals, an extraction unit configured to extract wavelength information corresponding to the detected wavelength identification signal and extract a driving condition of a wavelength-independent light source corresponding to the extracted wavelength information, and a driving unit configured to drive the wavelength-independent light source according to the extracted driving condition.

Abstract: A seed light module for a WDM-PON system is provided. The seed light module includes a reflector configured to reflect a part of seed light that is generated from a light source generator, and an optical attenuator configured to attenuate the intensity of the reflected seed light and provide the attenuated seed light, which corresponds to a signal generated by attenuating the intensity of the reflected seed light, to the light source generator.