Abstract: An optical signal receiving apparatus included in an optical line terminal (OLT) includes a resistor disposed between a capacitor connected to a receiving optical sub-assembly (ROSA) and a limiting amplifier, wherein a resistance value of the resistor may be determined based on the OLT receives an optical signal from an optical network unit (ONU) and whether the ONU transmitting the optical signal to the OLT is switched, the resistance value of the resistor may be determined to reduce a data loss occurring from the optical signal receiving apparatus in response to the OLT receiving the optical signal from the ONU, and the resistance value of the resistor may be determined such that the optical signal receiving apparatus more rapidly follows a change in intensity of the optical signal in response to the ONU transmitting the optical signal to the OLT being switched.

Abstract: An interface for transmitting a high-speed signal and an optical module including the same. The interface may include a main substrate and a sub-substrate. The main substrate may have at least one high-speed signal line formed on the upper surface of the main substrate. The sub-substrate may have a first conductive line formed on the lower surface thereof so as to adjust high-speed signal transmission characteristics of the high-speed signal line, wherein the first conductive line may be coupled to the upper surface of the main substrate and partially overlap with the high-speed signal line.

Abstract: A board assembly for transmitting a high-speed signal and a method of manufacturing the same. The board assembly may include a submount board, a base board, and a contact member for a signal line. The submount board may include at least one first high-speed signal line formed on the surface thereof. The base board may include the submount board on one part of the upper surface thereof, and at least second high-speed signal line on the other part of the upper surface thereof, wherein the second high-speed signal lines corresponds to the first high-speed signal lines, respectively. The contact member for the signal line may be installed on the side of the submount board, and have an upper portion contacting the first high-speed signal line and a lower portion contacting the second high-speed signal line such that the first high-speed signal line contacts the second high-speed signal line.

Abstract: A transmitting and receiving apparatus using a wavelength-tunable filter according to an exemplary embodiment may include: a filter to generate a filtered optical-reception signal by passing only an allowed-to-be-passed wavelength by using Bragg grating filter; a wavelength setter to set the allowed-to-be-passed wavelength of the filter; and a photoelectric converter to perform photoelectric conversion on the filtered optical-reception signal into an electrical signal.

Abstract: A cost-effective optical coupling module for achieving an optical coupling by providing a predetermined space between an optical element and an optical waveguide without an additional lens is provided. The cost-effective optical coupling module includes an optical element configured to output or receive an optical signal, a substrate configured to allow the optical element to be fixed to an upper surface of one side thereof, an optical waveguide disposed above the optical element and coupled to the optical element, and spacers protruding at both sides of the substrate to maintain an interval between the optical waveguide and the optical element.

Abstract: A board assembly for transmitting a high-speed signal and a method of manufacturing the same. The board assembly may include a submount board, a base board, and a contact member for a signal line. The submount board may include at least one first high-speed signal line formed on the surface thereof. The base board may include the submount board on one part of the upper surface thereof, and at least second high-speed signal line on the other part of the upper surface thereof, wherein the second high-speed signal lines corresponds to the first high-speed signal lines, respectively. The contact member for the signal line may be installed on the side of the submount board, and have an upper portion contacting the first high-speed signal line and a lower portion contacting the second high-speed signal line such that the first high-speed signal line contacts the second high-speed signal line.

Abstract: An interface for transmitting a high-speed signal and an optical module including the same. The interface may include a main substrate and a sub-substrate. The main substrate may have at least one high-speed signal line formed on the upper surface of the main substrate. The sub-substrate may have a first conductive line formed on the lower surface thereof so as to adjust high-speed signal transmission characteristics of the high-speed signal line, wherein the first conductive line may be coupled to the upper surface of the main substrate and partially overlap with the high-speed signal line.

Abstract: An optical network terminator of the present invention includes an optical wavelength division multiplexer for receiving an optical signal and incoherent light. An optical detection unit converts a downstream high speed and low speed optical signals into electrical signals. A laser diode converts an upstream signal into an optical signal. A high speed driving unit is supplied with power from a power supply unit to drive a forward-biased laser diode and establish a data and video channel. A high speed reception unit is supplied with the power to receive a downstream data and video channel. A charging unit outputs charged power at the time of a power failure. A low speed driving unit is supplied with the charged power to reverse-bias the laser diode to establish a voice channel. A low speed reception unit is supplied with the charged power to receive a voice channel.