Abstract: An apparatus for measuring fluid speed by using the refraction of light is disclosed. The apparatus includes: a channel in which a passage is formed to allow the flow of a fluid; a first and a second light source that are located in any one region of an upper part and a lower part of the channel; a sensor installed in an opposite region of the region where the first and second light sources are located with respect to the channel, to receive the light emitted from the first and second light sources; a speed calculation unit configured to calculate a speed of the fluid by using the intensity of the light received at the sensor.

Abstract: A bandwidth allocation apparatus and method for providing a low-latency service in an optical network that may guarantee low-latency requirements and improve a network utilization rate by allocating a static bandwidth to an ONU requiring low latency within an allocable bandwidth and by allocating a dynamic bandwidth to an ONU not requiring the low latency within a remaining bandwidth.

Abstract: A microfluidic circuit element comprising a microfluidic main channel and nano interstices is disclosed. The nano interstices are formed at both sides of the main channel and are in fluid communication with the main channel. The nano interstices have a height less than that of the main channel, gives more driving force of the microfluidic channel and provides stable flow of a fluid. The microfluidic circuit element may be made from a plastic material having a contact angle of 90 degrees or less. The microfluidic circuit element is particularly useful when filling a liquid sample to the channel which is empty or filled with air and shows greatly improved a storage stability.

Abstract: Wavelength channels used in the optical network system are classified into downstream channels used to transmit optical signals from an optical line terminal (OLT) to an optical network unit (ONU) and upstream channels that are used to transmit optical signals from the ONU to the OLT. The wavelength channels are included in an O-band and may not overlap each other. One of the upstream channels are allocated to a wavelength band (for example, a zero-dispersion window) in which a four-wave mixing occurs. A wavelength spacing between the upstream channels and the downstream channels is determined based on a performance of separating the upstream channels and the downstream channels in a bidirectional optical sub assembly (BOSA) of the ONU. Also, a wavelength spacing between the downstream channels is determined based on a performance of separating the downstream channels in the BOSA.

Abstract: An optical network unit (ONU) for optical transmission in a burst mode includes an electro-absorption modulated laser (EML) transmitter including a laser diode (LD) and configured to transmit an uplink optical signal through the LD, an electro-absorption modulator (EAM) driver integrated circuit (IC) (EAM driver IC) configured to amplify an uplink data signal and provide the amplified data signal to the EML transmitter, an LD burst-mode driving circuit configured to control an operation of turning on or off the LD based on a burst-enable signal, and a media access control (MAC) configured to transmit the data signal to the EAM driver IC and transmit the burst-enable signal to the LD burst-mode driving circuit.

Abstract: An optical line terminal (OLT) accumulates and stores a user frame for each physical layer identifier (PLID) to efficiently use a plurality of lanes used for downstream transmission from the OLT to an optical network unit (ONU). The OLT envelopes payloads that are accumulatively stored for the respective PLIDs based on a transmission rate supported by a corresponding ONU, combines an envelope header based on an envelope payload unit, and transmits an envelope frame. The OLT selects an available lane from among a plurality of lanes and may transmit the envelope frame through the selected lane.

Abstract: An optical network unit (ONU) for optical transmission in a burst mode includes an electro-absorption modulated laser (EML) transmitter including a laser diode (LD) and configured to transmit an uplink optical signal through the LD, an electro-absorption modulator (EAM) driver integrated circuit (IC) (EAM driver IC) configured to amplify an uplink data signal and provide the amplified data signal to the EML transmitter, an LD burst-mode driving circuit configured to control an operation of turning on or off the LD based on a burst-enable signal, and a media access control (MAC) configured to transmit the data signal to the EAM driver IC and transmit the burst-enable signal to the LD burst-mode driving circuit.

Abstract: A photonic crystal structure includes a nano structure layer including a plurality of nano particles of various sizes, and a photonic crystal layer on the nano structure layer. The plurality of nano particles are spaced apart from each other. The photonic crystal layer has a non-planar surface, and is configured to reflect light of a particular wavelength.

Abstract: An optical line terminal (OLT) accumulates and stores a user frame for each physical layer identifier (PLID) to efficiently use a plurality of lanes used for downstream transmission from the OLT to an optical network unit (ONU). The OLT envelopes payloads that are accumulatively stored for the respective PLIDs based on a transmission rate supported by a corresponding ONU, combines an envelope header based on an envelope payload unit, and transmits an envelope frame. The OLT selects an available lane from among a plurality of lanes and may transmit the envelope frame through the selected lane.

Abstract: A radio-over-fiber (RoF) transmission system includes at least one baseband unit (BBU) connected to a core network of a service provider that provides a mobile Internet service, an optical line terminal (OLT) configured to convert a radio signal received from the at least one BBU into an optical signal, an optical distribution network (ODN) comprising an optical fiber and an optical splitter, at least one optical network unit (ONU) configured to receive the optical signal from the OLT via the ODN and convert the optical signal into a radio signal, and at least one remote radio head (RRH) configured to receive the radio signal from the at least one ONU and output the radio signal via a plurality of antennas.

Abstract: A method of manufacturing an MRAM device includes sequentially forming a first insulating interlayer and an etch-stop layer on a substrate. A lower electrode is formed through the etch-stop layer and the first insulating interlayer. An MTJ structure layer and an upper electrode are sequentially formed on the lower electrode and the etch-stop layer. The MTJ structure layer is patterned by a physical etching process using the upper electrode as an etching mask to form an MTJ structure at least partially contacting the lower electrode. The first insulating interlayer is protected by the etch-stop layer so not to be etched by the physical etching process.

Abstract: A method of registering an optical network unit (ONU) in an optical line terminal (OLT). The OLT determines a lane to be used by the ONU based on a transmission rate supported by the ONU, combines or distributes data of a dataflow based on a rate of the lane by comparing the rate of the lane to a rate of the dataflow of a media access control (MAC) client interface, and, when the OLT and the ONU are connected through multiple lanes, transmits and receives data between the OLT and the ONU through channel bonding for more effective use of a network.

Abstract: A host unit is provided between a remote radio head and a radio unit. The host unit performs a conversion between a digital optical signal used by the remote radio head and an analog optical signal used by the radio unit. A frequency of the analog optical signal converted by the host unit may be an intermediate frequency. The radio unit performs a conversion between an analog optical signal used by the host unit and an analog radio signal used by a user terminal. A frequency of the analog radio signal may be included in a millimeter wave band or radio frequency band.

Abstract: The inventive concepts provide a method for forming a hard mask pattern. The method includes forming a hard mask layer on an etch target layer disposed on a substrate, forming a photoresist pattern having an opening exposing one region of the hard mask layer, performing an oxygen ion implantation process on the one region using the photoresist pattern as a mask to form an oxidized portion in the one region, and patterning the hard mask layer using the oxidized portion as an etch mask.

Abstract: Provided is an analog optical transmission system using a dispersion management technique. The analog optical transmission system may include a digital unit (DU) pool including a plurality of DUs to transmit an optical signal; a plurality of radio units (RUs) to receive the optical signal; and one or more dispersion management apparatus to remove a signal distortion component caused by an interaction between a chirp and chromatic dispersion by compensating for the chromatic dispersion before the plurality of RUs receives the optical signal that is transmitted from the DU pool.

Abstract: A microfluidic circuit element comprising a microfluidic main channel and nano interstices is disclosed. The nano interstices are formed at both sides of the main channel and are in fluid communication with the main channel. The nano interstices have a height less than that of the main channel, gives more driving force of the microfluidic channel and provides stable flow of a fluid. The microfluidic circuit element may be made from a plastic material having a contact angle of 90 degrees or less. The microfluidic circuit element is particularly useful when filling a liquid sample to the channel which is empty or filled with air and shows greatly improved a storage stability.

Abstract: An apparatus for transmitting a control signal in a radio-over-fiber (RoF)-based mobile fronthaul includes: a data channel transmitter configured to generate a data signal at a preassigned frequency or wavelength; a control channel transmitter configured to generate a control signal at a designated frequency or wavelength that is shared with other apparatuses; and a combiner configured to combine the data signal with the control signal.

Abstract: A remote radio head disposed between a baseband unit and a host unit. The remote radio head may transmit and receive a digital optical signal to the baseband unit, transmit and receive an analog optical signal to the host unit, and convert the digital optical signal and the analog optical signal, a frequency of the analog optical signal transmitted and received by the remote radio head and the host unit may be an intermediate frequency of a baseband, the host unit may be disposed between the remote radio head and a radio unit, the host unit and the radio unit may transmit and receive the analog optical signal, and the frequency of the analog optical signal transmitted and received by the host unit and the radio unit may be the intermediate frequency with a baseband signal.

Abstract: A microfluidic circuit element comprising a microfluidic main channel and nano interstices is disclosed. The nano interstices are formed at both sides of the main channel and are in fluid communication with the main channel. The nano interstices have a height less than that of the main channel, gives more driving force of the microfluidic channel and provides stable flow of a fluid. The microfluidic circuit element may be made from a plastic material having a contact angle of 90 degrees or less. The microfluidic circuit element is particularly useful when filling a liquid sample to the channel which is empty or filled with air and shows greatly improved a storage stability.

Abstract: A bidirectional optical element in optical network units (ONUs) of a passive optical network (PON) includes a main filter configured to pass an upstream signal having an upstream-channel wavelength and a downstream signal having a downstream-channel wavelength, a drop filter configured to pass the downstream signal having the downstream-channel wavelength and reject the upstream signal having the upstream-channel wavelength, and an add filter configured to pass the upstream signal having the upstream-channel wavelength and reject the downstream signal having the downstream-channel wavelength, wherein the main filter, the drop filter, and the add filter are configured to share a single optical waveguide, and the optical waveguide is configured to connect input ports of the main filter and the drop filter and an output port of the drop filter and is provided in a straight line shape.