Sumitomo Electric Industries, Limited

Ensphere Solutions, Inc.

Naruto Tanaka

Tomoyuki Funada

Daisuke Umeda

Shuitsu Yuda

Daisuke Kawase

Keisuke Jinen

An optical reception device includes: a light receiving element; an amplifier which receives and amplifies a current based on an input current from the light receiving element; a direct-current adjustment circuit which removes an offset current included in the input current; an alternating-current adjustment circuit which causes a part of the input current to flow therein; and a controller which controls the direct-current adjustment circuit and the alternating-current adjustment circuit. The controller includes an integrator configured to integrate an output of the amplifier and output a resultant output to two electric paths of a positive phase and a negative phase, and an inversion suppression circuit configured to operate so as to inject a current to the positive phase and extract a current from the negative phase when a negative phase potential of an output of the integrator is higher than a positive phase potential thereof.

Optical reception device, station-side device, PON system, preamplifier, optical reception method, and method for suppressing output inversion of integrator

An optical receiver module which receives a first optical signal including a continuous signal or a burst signal includes: a variable optical attenuator which adjusts the first optical signal to output a second optical signal; a semiconductor optical amplifier which amplifies the second optical signal to output a third optical signal; and a controller which controls an output of at least one of the variable optical attenuator and the semiconductor optical amplifier so as to cause the semiconductor optical amplifier to operate in a region in which gain saturation of the semiconductor optical amplifier does not occur, on the basis of at least one of: a power obtained by suppressing an outside portion of the wavelength band of the first optical signal in the third optical signal; and a power obtained by extracting the outside portion of the wavelength band of the first optical signal in the third optical signal.

Optical receiver module, optical receiving method, optical line terminal, PON system, and optical filter

A PON system according to one manner of the present invention includes an optical line terminal (OLT), at least one optical network unit (ONU), and an optical fiber that connects the optical line terminal and the optical network unit to each other. A reception level category for categorizing a reception level in the optical network unit, of an optical signal sent from the optical line terminal through the optical fiber is set. In discovery processing for searching for and registering an unregistered optical network unit, the optical line terminal registers an optical network unit corresponding to the reception level category.

PON system, optical network unit, optical line terminal, method of registering optical network unit, and data structure

A host board for mounting an optical transceiver includes a connector that is configured to attach thereto and detach therefrom an optical transceiver having at least one lane and includes electrical contacts as many as the at least one lane, a management unit configured to receive lane information regarding the at least one lane of the optical transceiver from the optical transceiver through the connector and specify an available electrical contact, and a communication unit configured to communicate with the optical transceiver through the connector. The communication unit is configured to communicate information with the optical transceiver through the electrical contact specified by the management unit.

Host board, optical receiver, optical transmitter, optical transceiver, and method of mounting optical transceiver on host board

A configuration for receiving transmission data at multiple rates where one rate is not necessarily a multiple of another is provided. A host board includes a receiving circuit, a cross point switch, and a switch control circuit. The receiving circuit includes a receiving unit configured to receive a first data signal transmitted at a first rate, and a second receiving unit configured to receive a second data signal transmitted at a second rate different from the first rate. The cross point switch includes input terminals and output terminals. The cross point switch is configured to define a path of signal between the input terminals and the output terminals to route an input data signal to at least one of the first receiving unit and the second receiving unit.

Data receiving apparatus

An optical receiver includes a light reception element for receiving an optical signal, a bias voltage supply/monitoring circuit for supplying a bias voltage to the light reception element and generating a monitoring voltage indicating magnitude of an output current of the light reception element, and a constant current source. The bias voltage supply/monitoring circuit is supplied with a remaining current obtained by subtracting the output current of the light reception element from an output current of the constant current source. The bias voltage supply/monitoring circuit converts the remaining current to the monitoring voltage.

Optical receiver and light reception current monitoring method

An optical communication module includes a modulation current supply circuit for supplying to a light-emitting element for transmitting a burst optical signal, a modulation current having magnitude in accordance with a logical value of data to be transmitted, a light-receiving element for monitoring, for outputting a current in accordance with intensity of light received from the light-emitting element, a measurement unit for measuring an output current from the light-receiving element for monitoring at set measurement timing, an adjustment unit for adjusting magnitude of the modulation current based on a result of measurement of the output current by the measurement unit, and a measurement timing setting unit for setting measurement timing based on a control signal for controlling transmission of the burst optical signal.

Optical communication module, optical network unit, and method of controlling light-emitting element

In the present invention, wasted power consumption caused when a clock and data recovery unit in an optical network unit in a PON system is activated from a power-saving state is reduced and rapid, secure communication is performed. A clock and data recovery unit includes a phase-locked loop that can be set to normal mode or power-saving mode and that includes a voltage-controlled oscillator and recovers a clock signal and a data signal from input signals. The clock and data recovery unit includes a reference clock multiplier circuit that multiplies a reference clock signal and outputs the multiplied reference clock signal; and a frequency training loop that includes the same voltage-controlled oscillator and performs synchronous oscillation training by the voltage-controlled oscillator using the reference clock multiplier circuit before the phase-locked loop transitions from power-saving mode to normal mode.

Clock and data recovery unit and power control method therefor and PON system

A receiving unit using a voltage-controlled oscillator is allowed to compensate for the frequency characteristics of the voltage-controlled oscillator resulting from temperature change, without adding a capacitive element for temperature compensation. A receiving unit and an optical line terminal include a clock and data recovery circuit that extracts a clock signal and a data signal from a received signal, and have: a calibrator that calibrates an oscillation frequency of a voltage-controlled oscillator included in the clock and data recovery circuit; and a managing unit having a function of managing a schedule for receiving signals, the managing unit selecting a time where a duration of a certain state meets a time required for calibration by the calibrator to thereby output a reset signal (calibration instruction signal) to the calibrator, the state having no received signal (upstream signal) from which a clock signal and a data signal are to be extracted.

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Osaka, Japan

Naruto Tanaka