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

Abstract: An exemplary embodiment of the present disclosure provides an optical module including: an optical hybrid including a metal optical waveguide; a photo detector configured to receive light; and a platform including an optical hybrid supporting section for supporting the optical hybrid, a photo detector supporting section for supporting the photo detector, and an inclined surface configured to change a propagation direction of light emitted from the optical hybrid, and configured to combine the optical hybrid and the photo detector.

Abstract: The present disclosure relates to a planar optical waveguide element, and more particularly, to an optical waveguide end structure for effective optical signal connection with a light source, a light receiving element, or a different type of optical waveguide element. According to an exemplary embodiment of the present disclosure, there is disclosed an optical waveguide structure, including: a planar optical waveguide including a lower clad, a waveguide core formed on the lower clad, and a clad layer formed on the waveguide core; and an optical lens formed on a surface of the clad layer. One end of the optical waveguide forms an inclined surface having a predetermined inclination angle.

Abstract: Provided is an electronic device that includes an LTCC inductor including a first sheet disposed on a substrate and including a first conductive pattern, a second sheet disposed on the first sheet and including a second conductive pattern, and a via electrically connecting the first conductive pattern to the second conductive pattern, and a spacer disposed on a lower surface of the first sheet to provide an air gap between the substrate and the first sheet, wherein the first conductive pattern is exposed out of the lower surface of the first sheet.

Abstract: A method for fabricating a semiconductor package, includes the steps of forming a first terminal at a first substrate; mixing a polymer resin and solder particles to provide a mixture; covering at least one of an upper surface and side surfaces of the first terminal with the mixture; and heating the first substrate at a temperature higher than a melting point of the solder particles of the mixture to form a solder layer that covers the at least one of an upper surface and a side surface of the first terminal. The solder particles flow or diffuse toward the terminal in the heated polymer resin to adhere to at least some of the exposed surfaces of the terminal thereby forming the solder layer. The solder layer improves the adhesive strength between the terminals of the semiconductor chip and the substrate in the subsequent flip chip bonding process.

Abstract: Provided is a filling composition. The filling composition includes: a first particle including Cu and/or Ag; a second particle electrically connecting the first particles; and a resin containing a high molecular compound, a hardener, and a reducer, in which the first and second particles are dispersed, wherein the hardener includes amine and/or anhydride, and the reducer includes carboxyl.

Abstract: Provided are an adapter assembly and method for compensating optical fibers for a length difference. The adapter assembly includes a first adapter, a second adapter, and a member. The first adapter is configured to be connected to at least one optical communication unit. The second adapter is configured to be connected to at least another optical communication unit and be coupled to the first adapter. The member is configured to be interposed between the first and second adapters for providing an optical signal transmission path between the optical communication units. Owing to the member, a length difference between optical fibers can be compensated for.

Abstract: Provided is an optical OFDM receiver. The optical OFDM receiver receives an optical signal dependent on the nonlinearity of a transmitter. The optical OFDM receives includes an optical down converter, a nonlinearity compensator, and an OFDM demodulator. The optical down converter converts the optical signal into an electrical signal. The nonlinearity compensator filters the electrical signal, for compensating distortion which is added to the optical signal when the transmitter performs optical modulation. The OFDM demodulator demodulates the distortion-compensated electrical signal in an OFDM scheme.

Abstract: Provided is a polarization division multiplexed optical OFDM transmitter. The polarization division multiplexed optical OFDM transmitter includes a data demultiplexer, a training symbol generation unit and an optical up-converter and polarization division multiplexing unit. The data demultiplexer divides a transmission signal into a plurality of groups. The training symbol generation unit allocates a plurality of training symbols for each OFDM data which is included in the respective multiplexed groups, and allocates repetitive data in a time domain for the respective training symbols for data of 0 to periodically appear for the respective training symbols in a frequency domain. The optical up-converter and polarization division multiplexing unit performs optical frequency band conversion and polarization division multiplexing on an output of the training symbol generation unit to output a polarization division multiplexed optical OFDM signal corresponding to a plurality of polarization components.

Abstract: Provided is a method and structure for bonding a flip chip while increasing the manufacturing yield. In the method, solder bumps are formed on first electrodes and/or second electrodes disposed on first and second substrates, respectively. In addition, the first and second electrodes are arranged to face each other with a second resin including spacer balls being disposed between the first and second substrates. In addition, while flowing the second resin, the first and second substrates are pressed until the distance between the first and second substrates is decreased smaller than diameter of the spacer balls so as to connect the solder bumps between the first and second electrodes.

Abstract: Provided is an optical receiver used for an optical communication system, more particularly, a polarization split-phase shift demodulation coherent optical receiver. An optical hybrid includes a first optical splitter, a phase shift waveguide, a second optical splitter, and an optical coupler. The first optical splitter splits a first input optical signal to output first output optical signals. The phase shift waveguide receives the first output optical signals and controls and outputs the first output optical signals such that the first output optical signals have different phases. The second optical splitter splits a second input optical signal to output a plurality of second output optical signals. The optical coupler couples the first output optical signals one-to-one with the second output optical signals, respectively.

Abstract: Provided is an electronic device that includes an LTCC inductor including a first sheet disposed on a substrate and including a first conductive pattern, a second sheet disposed on the first sheet and including a second conductive pattern, and a via electrically connecting the first conductive pattern to the second conductive pattern, and a spacer disposed on a lower surface of the first sheet to provide an air gap between the substrate and the first sheet, wherein the first conductive pattern is exposed out of the lower surface of the first sheet.

Abstract: Provided is a method for fabricating semiconductor package and a semiconductor package fabricated using the same. The method for fabricating semiconductor package dopes a mixture including the polymer material and the solder particle on the substrate in which the terminal is formed and applies heat, and thus the solder particle flows (or diffuses) toward the terminal in the heated polymer resin to adhere to the exposed surface of the terminal, i.e., the side surface and upper surface of the terminal, thereby forming the solder layer. The solder layer improves the adhesive strength between the terminal of the semiconductor chip and the terminal of the substrate in the subsequent flip chip bonding process.

Abstract: Provided are a method and device for separating and converting multiband signals. The device includes a photoelectric converter for converting an externally received optical signal into an electrical signal, a first switch for separating the converted electrical signal into signals according to frequency bands, a first mobile communication band-pass amplifier for amplifying a mobile communication network signal of the signals separated by the first switch, a broadband up-converter for up-converting a baseband signal of the signals separated by the first switch into a broadband signal, a first broadband amplifier for amplifying the broadband signal output from the broadband up-converter, and a transmitter for wirelessly transmitting the signals amplified by the first mobile communication band-pass amplifier and the first broadband amplifier.

Abstract: Provided are a buried capacitor, a method of manufacturing the same, and a method of changing a capacitance thereof. The buried capacitor includes an upper electrode including at least one first hole, a lower electrode including at least one second hole, and a dielectric interposed between the upper electrode and the lower electrode.

Abstract: Provided are an inductor, which is vertically formed, and an electronic device having the inductor, and more particularly, an inductor capable of minimizing loss of a surface area and accomplishing high efficiency impedance by vertically forming the inductor in a plurality of insulating layers, and an electronic device having the same. The inductor includes a plurality of conductive lines disposed in the insulating layers; and vias vertically formed in the insulating layers to electrically connect the plurality of conductive lines. When a board or an electronic device including an inductor proposed by the present invention is manufactured, the inductor can occupy a minimum area in the electronic device or board while providing high inductance. In particular, the surface area of the electronic device or board occupied by the inductor can be remarkably decreased to reduce manufacturing costs.

Abstract: Provided is a microstrip patch antenna. The microstrip patch antenna includes a dielectric layer, a feed circuit disposed in the dielectric layer, at least one slot disposed in the dielectric layer and vertically spaced apart from the feed circuit, and a patch antenna disposed outside the dielectric layer and vertically spaced apart from the at least one slot.

Abstract: A channel switching function is added to a wavelength division multiplexing passive optical network (WDM-PON) system, which is an access optical network system, and the potential transmission rate is increased by combining wide wavelength tunable lasers and a time division multiplexing (TDM) data structure and properly using the necessary optical components. In addition, when the wavelength of a light source or an arrayed waveguide grating (AWG) changes, the wavelength is traced and the magnitude of a transmitted signal is maximized without an additional detour line using a loop-back network structure. Furthermore, fewer thermo-electric controllers (TECs) are required for stabilizing the temperature of an optical line terminal (OLT) using wavelength tunable lasers, each laser electrically changing its wavelength.

Abstract: An electroabsorption (EA) duplexer in which an optical amplifier, a photodetector, and an optical modulator are monolithically integrated to obtain a high radio frequency (RF) gain in radio-over fiber (RoF) link optical transmission technology is provided. The EA duplexer includes a substrate, a separation area, an optical detection/modulation unit, and an optical amplification unit. The separation area includes a first epitaxial layer formed of at least one material layer on the substrate. The first epitaxial layer functions as a first optical waveguide. The optical detection/modulation unit includes a second epitaxial layer formed of at least one material layer on the first epitaxial layer to detect and modulate an optical signal. The second epitaxial layer functions as a second optical waveguide. The optical amplification unit includes the second optical waveguide and a third epitaxial layer formed of at least one material layer on the second epitaxial layer to amplify an optical signal.

Abstract: Provided is an optical module used in a communication system employing a radio over fiber (ROF) technology delivering a radio frequency (RF) signal through an optical fiber. The optical module includes: an optical device; a signal line for transporting a radio frequency (RF) signal input from an external circuit to the optical device; and a resistor separately disposed from the signal line and having one end connected with the optical device, wherein the input impedance seen from the signal line is matched by the resistor. A bias voltage supplied to operate the optical device is applied through an inductor connected to the signal line between the optical device and a filter. Here, the filter formed by a pattern of the signal line prevents the bias voltage from being supplied to the external circuit. In order to amplify the RF signal input from the external circuit, an amplifier may be connected between the external circuit and the filter.