Abstract: Disclosed is an apparatus and method for linearly controlling the output gain of an optical receiver in an optical communication system. The gain control apparatus includes: a light-receiving device for converting an input optical signal into a current signal and outputting the current signal; a signal detection means for outputting a voltage signal corresponding to intensity changes in the current signal; an attenuation-degree determination means for determining a degree of attenuation of an RF signal restored from the current signal based on the voltage signal; and an amplification unit for amplifying and outputting the restored RF signal. Therefore, a broadcasting signal can be stably provided since the gain of the optical receiver is linearly controlled, and the circuit configuration of the optical receiver can be simplified since the gain of the optical receiver is controlled by a circuit having a relatively simple configuration.

Abstract: A method and apparatus for compensating for temperature characteristics of a laser diode are disclosed. The laser diode may be used in a transmitter unit of a transceiver for optical signal transmission. The transceiver includes the laser diode and a monitor photodiode. In such a method, a modulation current is derived from an input voltage and arbitrary variables. Variations of overall modulation resistance values corresponding to an operation temperature range are evaluated by a relation between the modulation current and the overall modulation resistance, and the overall modulation resistance values are determined according to the variations. Also, variations of overall bias resistance values corresponding to the temperature range are evaluated by a current Impd of the photodiode, which is derived at specific optical power arbitrarily chosen in the temperature range. The overall bias resistance values are determined according to the variations.

Abstract: An optical power equalization method and an optical power equalizer for optical signals traveling upstream in a passive optical network are disclosed. The equalizer includes a wavelength coupler, an optical splitter, an optical detector, an active gain control circuit, a delay element, and an optical amplifier. The wavelength coupler separates an upstream optical signal from a single optical fiber. The optical splitter transfers a part of the optical signal to the optical detector. The optical detector converts the optical signal from the coupler into an electrical signal having an amplitude proportional to the optical signal's intensity. The control circuit controls a driving current to be provided to the amplifier, according to the electrical signal's amplitude. The delay element delays the optical signal by a time required for the optical detector and the control circuit to perform their operation.

Abstract: The invention relates to a multi-layer structure used in an optical communication field and its manufacturing method in which the capacitance effect between the metal patterns of a Silicon Optical Bench (SiOB) is significantly reduced. The multi-layer structure includes a dielectric layer and conductive patterns on a semiconductor substrate, such that the conductive patterns are separated from each other, wherein the dielectric layer and upper portions of the semiconductor substrate between the conductive patterns are etched out to a predetermined thickness to effectively reduce the capacitance without changing the area or structure of the metal patterns.

Abstract: The invention relates to a multi-layer structure used in an optical communication field and its manufacturing method in which the capacitance effect between the metal patterns of a Silicon Optical Bench (SiOB) is significantly reduced. The multi-layer structure includes a dielectric layer and conductive patterns on a semiconductor substrate, such that the conductive patterns are separated from each other, wherein the dielectric layer and upper portions of the semiconductor substrate between the conductive patterns are etched out to a predetermined thickness to effectively reduce the capacitance without changing the area or structure of the metal patterns.

Abstract: The invention relates to a multi-layer structure used in an optical communication field and its manufacturing method in which the capacitance effect between the metal patterns of a Silicon Optical Bench (SiOB) is significantly reduced. The multi-layer structure includes a dielectric layer and conductive patterns on a semiconductor substrate, such that the conductive patterns are separated from each other, wherein the dielectric layer and upper portions of the semiconductor substrate between the conductive patterns are etched out to a predetermined thickness to effectively reduce the capacitance without changing the area or structure of the metal patterns.

Abstract: The invention relates to a multi-layer structure used in an optical communication field and its manufacturing method in which the capacitance effect between the metal patterns of a Silicon Optical Bench (SiOB) is significantly reduced. The multi-layer structure includes a dielectric layer and conductive patterns on a semiconductor substrate, such that the conductive patterns are separated from each other, wherein the dielectric layer and upper portions of the semiconductor substrate between the conductive patterns are etched out to a predetermined thickness to effectively reduce the capacitance without changing the area or structure of the metal patterns.

Abstract: An air conditioner having a suction grille member for opening and closing suction inlets of a main body and at least one pair of electric dust collectors installed behind the suction grille member for convenient attachment or detachment for cleaning, the air conditioner comprising: a suction grille member coupled to the main body by means of a plurality of hinge parts for being horizontally opened or closed in the opening and closing method; and at least one accommodating member fixed behind the suction grille member for accommodating and supporting the electric dust collectors as soon as the suction grille member opens, whereby the electric dust collectors are pulled out to a side for cleaning and are returned to their original positions in convenience.

Abstract: A color filter substrate for a liquid crystal display device is obtained by patterning color filters on a transparent substrate, selective-coating an overcoat layer on the substrate, and forming a common electrode and a black matrix to be connected each other, without any further step. This color filter substrate compensates a high sheet resistance of the common electrode and reduces a crosstalk and a surface reflection rate of the panel. In addition, the black matrix is formed on the color filters, and thus the reduction of the resistance of the common electrode is available. A process for forming the ITO layer on the black matrix is only required as an additional process, so that the step coverage is improved and thus no polyimide-off phenomenon is resulted during the rubbing process, while improving poor quality pixels which may be produced by the light leak and the polyimide-off.