Fujitsu Corporation

Canon Anelva Corporation

Yuji Shimada

Takuji Maeda

Hiroaki Tomofuji

Takeshi Sakamoto

Ichiro Nakajima

Ayumu Nonaka

Kosuke Komaki

Megumi Nakamura

Yoshinobu Matsukawa

Hideo Kuroda

Masanori Kondoh

Taro Asao

Miwa Taniguchi

Koji Nekoda

Kouji Nekoda

Yoshiyuki Takizawa

Masayuki Sugiyama

Hiroki Mita

Yuki Ban

Syed Faruk Ahmed

A transmission device for which a work path is established in a first degree and a protection path is established in a second degree includes: a switch equipped with a plurality of optical ports; an optical signal generator, optically connected to a first optical port, and configured to generate an optical signal that is transmitted through the work path; and a monitor light generator, optically connected to a second optical port, and configured to generate monitor light by using a wavelength tunable light source. The monitor light generator controls a wavelength of the monitor light to be substantially the same as a wavelength of the optical signal. The switch guides the optical signal that arrives at the first optical port toward the first degree and guides the monitor light that arrives at the second optical port toward the second degree.

Device, system and method for transmitting wavelength division multiplexed optical signal

A mass spectrometer includes: an ionization unit configured to ionize an analyte gas; a filter unit configured to allow passage of only a target ion which is a component of the analyte gas ionized in the ionization unit and which has a specific mass-to-charge ratio; and an ion detection unit configured to detect an ion detection value based on the target ion having passed through the filter unit, wherein the ion detection unit includes a Faraday electrode which includes an electrode portion disposed along a centerline of the filter unit and a bottom electrode provided at a position downstream of the electrode portion in a flow of the target ion, the electrode portion and the bottom electrode being connected to each other, a secondary electron multiplier provided to face the electrode portion with the centerline located therebetween, and a blocking portion connected to the bottom electrode.

Mass spectrometer

There is provided an optical transmission device which includes a determiner, a convertor, and a switch. The determiner determines whether a frame includes a fixed stuff byte area or not when the frame is received from a first network, where the frame includes a payload area for storing client data and the fixed stuff byte area is for storing fixed data. When the determiner determines that the frame includes the fixed stuff byte area, a convertor to convert a fixed stuff byte area into the payload area and a switch switches a clock frequency from a first clock frequency used in the first network to a second clock frequency used in a second network when the frame including the converted fixed stuff byte area is output to the second network on the basis of the clock frequency as a reference.

Optical transmission device and optical transmission method

An optical transmission apparatus includes an extractor that extracts information indicating port allocation to each slot of a reception signal; a comparator that based on the extracted information and for a given slot among the slots, obtains a count of the slots allocated the same port as the given slot and compares the obtained count of slots and an expected value for the given slot; and a memory that stores therein for each slot, an expected value for the count of slots allocated the same port as the slot. The comparator detects a mismatch concerning the given slot, when the obtained count of slots and the expected value for the given slot differ.

Optical transmission apparatus and optical transmission method

A system and method of transmitting client data encoded according to an 8B/10B encoding between a client side and an optical communication network side, including inserting padding signals in an amount corresponding to a rate difference between a clock on the client side and a clock in the optical transmission device and controlling a clock to be used as a reference in transmitting the client data to synchronize with a clock having been used as a reference in transmitting the client data on the basis of a ratio of padding signals having been inserted in the client data.

Optical transmission device, optical transmission system, and bandwidth control method

During initial start-up of an optical communication system, an ASE reference span loss is calculated based on transmitting power and received power of ASE light generated by an optical amplifier, and an OSC reference span loss is calculated based on the transmitting power and the received power of OSC light. During normal operation of the optical communication system, a span loss is calculated using the OSC light, and an amount of change in the span loss representing a difference between the span loss and the OSC reference span loss is calculated. A current span loss between a transmitting station and a receiving station is calculated by adding the amount of change in the span loss to the ASE reference span loss.

Method for measuring optical characteristics and system thereof

The present invention relates to prevention of erroneous connection in an optical network and, in particular, it provides an optical communication node having route switching function as well as an optical network system using the same in a wavelength division multiplex (WDM) network system. There is provided an optical communication node that is connected to a specific optical path in an optical network, the optical communication node having: an external network that is placed thereunder; and an interruption part for interrupting connection between the optical network and the external network, wherein the interruption part interrupts the connection until a sequence of changing a route is completed when the route setting of the optical path is changed.

Optical communication node and optical network system

An optical transmission device includes: an attenuator that attenuates an optical signal from an adjacent optical transmission device; an optical element that is arranged downstream of the attenuator; a detector that detects a change in a characteristic of a transmission path; and a controller that adjusts, when the change is detected, an attenuation of the attenuator to keep the level of the optical signal input to the optical element at a predetermined level.

Optical transmission device for controlling optical level of transmission signal in optical transmission system

An optical transmission device includes: an attenuator that attenuates an optical signal before being input into an optical element by a predetermined attenuation amount determined so that a level of an adjustment optical signal input into the optical element falls within a predetermined dynamic range of the optical element; and a controller that adjusts the predetermined attenuation amount so that a level of the optical signal input into the optical element falls within the predetermined dynamic range.

In an optical signal level control apparatus used in a WDM system, the amount of circuitry per wavelength is reduced. Optical power level is detected on the output side of a variable optical attenuator, and the amount of attenuation in the variable optical attenuator is adjusted so that the output level becomes equal to a constant value L1. At this time, if the detected level is lower than a threshold value Th0 or Th-d, it is determined that a signal off condition has occurred, and the amount of attenuation is set to a constant value A1. The amount of attenuation, A1, is chosen to be sufficiently larger than the amount of attenuation used in the output level constant control but small enough to be able to detect the restoration of the signal. When the amount of attenuation is being held at the constant value A1, if the output level is restored to a level higher than the threshold value Th0 or Th1 (Th1&#x3c;Th-d), the output constant control is resumed.

Optical signal level control apparatus

A method for switching a transmission route in an optical network. A regenerator station extracts a main signal, and detects the input level of the main signal. When the input level falls below a threshold, the regenerator station determines that a failure occurs, and stops output of a main signal from the regenerator station, and transmits a control signal indicating occurrence of the failure to a receiver station, which separates the control signal from a main signal transmitted thereto, detects the input level of the main signal at the receiver station, analyzes the separated control signal, and determines whether or not a failure occurs. When the input level of the main signal at the receiver station falls below a threshold, or when the separated control signal indicates occurrence of a failure, the receiver station detects the occurrence of the failure, and switches the transmission route.

Method for switching transmission route, and optical transmission device

An optical transmission network includes a first dispersion compensator arranged in a maximum dispersion span having a maximum dispersion value and searched out from within a maximum dispersion route having a maximum dispersion value from among routes of non-regeneration intervals within which a dispersion value before dispersion compensation does not satisfy an upper limit of a dispersion tolerance, and a second dispersion compensator arranged in a maximum dispersion span having a maximum dispersion value searched out from within a maximum dispersion route having a maximum dispersion value from among the routes when a dispersion compensator is successively arranged until a route of a non-regeneration interval within which a dispersion value of a certain channel does not satisfy the dispersion tolerance does not remain any more based on the dispersion value after the dispersion compensation with respect to the searched out maximum dispersion span. The dispersion compensation amounts of the first and second dispersion compensators are such that, when the dispersion compensation amount of the maximum dispersion span in which the first and second dispersion compensators are arranged is successively increased, the span has a residual dispersion value equal to or higher than a fixed range and the maximum dispersion route which relates to the spans has a residual dispersion value which satisfies the dispersion tolerance or the span has a residual dispersion value which is within the fixed range.

Optical transmission network, optical transmission apparatus, dispersion compensator arrangement calculation apparatus and dispersion compensator arrangement calculation method

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Kawasaki, Japan

Yuji Shimada