Abstract: A method and apparatus to display a status of an optical recording and/or reproducing apparatus. The method includes, determining a type of an optical disc loaded into a tray; transmitting a predetermined signal based on the determination result to a laser emitting diode module comprising at least two laser emitting diodes, which emit different color beams so that the laser emitting diode module emits a color beam based on the determined type of the optical disc.

Abstract: Provided is a power control method for a mobile Radio Frequency Identification (RFID) reader and an RFID reader using the same. The RFID reader includes: an RFID reader transmission/reception control unit for creating a message to be transmitted to an RFID tag and transmitting RFID tag information to a terminal control unit; a reader transmitting unit for encoding and modulating the created message; a power amplifier for amplifying an output signal; a reader receiving unit for demodulating and decoding the signal and transmitting the signal to the RFID reader transmission/reception control unit; and an RFID reader power control unit for controlling power, wherein when the RFID reader transmission/reception control unit receives a command for acquiring the RFID tag information, the RFID reader power control unit applies power to the power amplifier.

Abstract: Provided is a method of exposing a wafer using a scan-type exposure apparatus. The method includes scan exposing a first shot selected from a first shot column formed of an array of shots disposed in a row in a first direction. The first shot column may be included in a plurality of shots repeatedly formed in the first direction and a second direction that are substantially orthogonal to each other in an exposure target area on the wafer. The method further includes scan exposing a second shot that is included in a second shot column and disposed in a diagonal direction to the first shot. The second shot column may be formed of an array of shots disposed in a row in the first direction and is closer to the first shot column than any other shot in the plurality of shots.

Abstract: Provided is a method for estimating the number of tags in a slotted Aloha-based RFID system, which can estimate the number of tags through a new statistical average scheme using the number of slots, the measured number of empty slots, and the measured number of ID slots. The estimating method includes the steps of: a) setting the number (N) of slots, the measured number (c0) of empty slots, and the measured number (c1) of ID slots as parameters; and estimating the number (n) of the tags by substituting the set values into n=(N?1)/(c0/c1).

Abstract: Provided are a tag signal receiving apparatus that can perform digital Amplitude Shift Keying (ASK) demodulation onto signals received in a tag, decode the demodulated tag signal in synchronization, and acquire tag data in a mobile RFID reader, and a method thereof. The tag signal receiving apparatus includes: a digital demodulating block for performing ASK demodulation onto a digital tag signal received through a reader antenna and converted into a digital tag signal in an analog-to-digital (AD) converter; and a decoding block for detecting edge position information of the demodulated tag signal by performing accumulation and decoding the demodulated tag signal by using the detected edge position information. The digital demodulating block includes a channel level comparator, a phase inverter, a signal converter; and an adder. The decoding block includes an edge information detector, a correlator, and a bit data decider.

Abstract: Provided is a method for securing information between a Radio Frequency Identification (RFID) reader and tag, and an RFID Reader and tag using the same. The method includes the steps of: a) requesting an access password of the RFID tag in the RFID reader; b) extracting a key value mapped to the access password transmitted from the RFID tag and transmitting the key value to the RFID tag in the RFID reader; c) outputting a hash function value from the key value transmitted from the RFID reader in the RFID tag; and d) determining whether to allow the RFID reader to access to an RFID tag memory based on whether the outputted hash function value is the same as the access password of the RFID tag.

Abstract: Provided are a mobile RFID reader and a control method thereof. The mobile RFID reader includes: a reader controller for beginning a reader operation to communicate with a tag in response to a command of a terminal controller of the wireless communication terminal; an anti-collision state machine for controlling collision among a plurality of tags, and transferring the result of communication with the tag to the reader controller; a reader transmitter for generating a reader command message decided at the anti-collision state machine, and coding and modulating the generated reader command message; a reader receiver for demodulating and decoding a tag signal received through an antenna, and reporting a tag response state to the anti-collision state machine; and a channel controller for selecting a channel to use to communicate with a tag in response to a command of the reader controller.

Abstract: An apparatus and method for reading multiple tags with different protocols in a RFID system are provided. The method of reading multiple tags with different protocols in a RFID system including the steps of: a) setting scheduling parameters including target protocols to read, priorities of each protocol, and information about a scheduling algorithm mode for reading multiple tags; b) reading tags of a single protocol corresponding to the target protocol when the scheduling algorithm mode is a single mode; and c) reading multiple tags by the target protocols when the scheduling algorithm mode is a multi mode.

Abstract: Provided is a Radio Frequency identification (RFID) system and method for protecting information. The system includes: an identification information storing unit which includes identification information and generates an interrupt/interference signal to block access without permission; an RFID calling unit which reads information of the identification information storing unit by loading a basic protocol and a security protocol for recognizing the identification information storing unit; and a storing unit which registers and stores information required for authentication between the RFID calling unit and the identification information storing unit, and information required for access control.

Abstract: A gain-clamped semiconductor optical amplifier includes a semiconductor optical amplifier for amplifying an inputted optical signal and outputting amplified spontaneous emission light, the amplified spontaneous emission light consisting of a first portion and a second portion, the first portion having a wavelength range to be amplified. The amplifier further includes a wavelength selective reflector for allowing the first portion of the amplified spontaneous emission light to pass through the wavelength selective reflector and reflecting the second portion of the amplified spontaneous emission light again to the semiconductor optical amplifier, thereby clamping the gain of the amplifier.

Abstract: A semiconductor optical amplifier for amplifying input optical signals is disclosed. The optical amplifier includes a substrate; a first active layer laminated on the substrate for generating pumping lights; a second active layer laminated on the substrate being gain-clamped by the pumping light and amplifying the input optical signals; and a grating formed on an upper portion of the substrate, adjacent to a boundary between the first active layer and the second active layer, for partially allowing the transmission of the pumping lights to the second active layer and partially reflecting the pumping lights.

Abstract: The present invention relates to an optical communication, and more particularly, to a wideband wavelength division multiplexing (WDM) optical communication system which can have a broad amplification band while overcoming a polarization dependency and solving a signal leakage between channels. In an optical amplifier module and optical transmission system for a WDM optical communication system using this, the optical amplifier module uses a semiconductor quantum dot optical amplifier as an amplifying means, and thus has a wide amplification bard and has no a polarization dependency of a gain and a signal leakage between channels, and the optical transmision system uses a semiconductor quantum dot optical amplifier module when several optical amplifier modules are connected for use so that a gain automatically becomes flat and automatically becomes fixed even though a channel number and an input signal size become different.

Abstract: The present invention provides an apparatus and method for compensating for the variation of a gain spectrum attributable to the temperature variation of a fiber amplifier, and a long-wavelength band dispersion-compensating hybrid amplifier equipped with the gain spectrum compensating apparatus. The apparatus includes a DCF located between a first amplification stage and a second amplification stage to compensate for dispersion of an optical signal output from the first amplification stage and perform Raman amplification of the optical signal using input pumping light; at least one pumping light provision means for providing forward or backward pumping light to the DCF; first and second temperature detection means for detecting temperature variations of the first and second amplification stages, respectively; and control means for controlling intensity of the pumping light of the pumping light provision means according to the detected temperature variations.

Abstract: A semiconductor optical amplifier for amplifying input optical signals is disclosed. The optical amplifier includes a substrate; a first active layer laminated on the substrate for generating pumping lights; a second active layer laminated on the substrate being gain-clamped by the pumping light and amplifying the input optical signals; and a grating formed on an upper portion of the substrate, adjacent to a boundary between the first active layer and the second active layer, for partially allowing the transmission of the pumping lights to the second active layer and partially reflecting the pumping lights.

Abstract: Disclosed is a gain-clamped semiconductor optical amplifier including a semiconductor optical amplifier for amplifying an inputted optical signal and outputting amplified spontaneous emission light, the amplified spontaneous emission light consisting of a first portion and a second portion, the first portion having a wavelength range to be amplified and a wavelength selective reflector for allowing the first portion of the amplified spontaneous emission light to pass through the wavelength selective reflector and reflecting the second portion of the amplified spontaneous emission light again to the semiconductor optical amplifier, thereby clamping the gain of the semiconductor optical amplifier.

Abstract: Provided is a method of exposing a wafer using a scan-type exposure apparatus. The method includes scan exposing a first shot selected from a first shot column formed of an array of shots disposed in a row in a first direction. The first shot column may be included in a plurality of shots repeatedly formed in the first direction and a second direction that are substantially orthogonal to each other in an exposure target area on the wafer. The method further includes scan exposing a second shot that is included in a second shot column and disposed in a diagonal direction to the first shot. The second shot column may be formed of an array of shots disposed in a row in the first direction and is closer to the first shot column than any other shot in the plurality of shots.

Abstract: A metro wavelength division multiplexing network is disclosed and includes a plurality of optical repeaters, connected through an optical-fiber link, each of the optical repeaters having a Raman-gain medium for Raman-amplifying an inputted optical signal, and a semiconductor optical amplifier for amplifying the Raman-amplified optical signal, wherein each of the optical repeaters accepts a pump light having a designated wavelength for pumping the corresponding Raman-gain medium.

Abstract: A method and apparatus to display a status of an optical recording and/or reproducing apparatus. The method includes, determining a type of an optical disc loaded into a tray; transmitting a predetermined signal based on the determination result to a laser emitting diode module comprising at least two laser emitting diodes, which emit different color beams so that the laser emitting diode module emits a color beam based on the determined type of the optical disc.

Abstract: The present invention relates to an optical communication, and more particularly, to a wideband wavelength division multiplexing (WDM) optical communication system which can have a broad amplification band while overcoming a polarization dependency and solving a signal leakage between channels. In an optical amplifier module and optical transmission system for a WDM optical communication system using this, the optical amplifier module uses a semiconductor quantum dot optical amplifier as an amplifying means, and thus has a wide amplification bard and has no a polarization dependency of a gain and a signal leakage between channels, and the optical transmision system uses a semiconductor quantum dot optical amplifier module when several optical amplifier modules are connected for use so that a gain automatically becomes flat and automatically becomes fixed even though a channel number and an input signal size become different.

Abstract: A resist pattern having a good form without any T-top or round top is obtained by coating on a photoresist layer an anti-reflective coating composition containing at least (a) polyacrylic acid, (b) polyvinyl pyrrolidone, (c) CnF2n+1COOOH (wherein n represents an integer of 3 to 11) and (d) tetramethylammonium hydroxide to form an anti-reflective coating, and conducting patternwise exposure and development.