[Problem] To provide an optical transmission/reception device, an optical communication system, an optical communication method, and a program which are capable of securing the confidentiality of information included in an optical signal even when the optical signal is transferred to a device that is not an original transmission destination device. [Solution] This optical transmission/reception device is provided with: a wave separation unit for receiving a wavelength-multiplexed optical signal and separating the same into a plurality of optical signals; a plurality of reception units for receiving each of the plurality of optical signals separated by the wave separation unit; a plurality of output units for outputting optical signals differing in wavelength from each other; a control unit for requesting, in response to the inclusion in the received wavelength-multiplexed optical signal of an optical signal to which a prescribed process has been applied, that a prescribed change be applied to the optical signal outputted by at least one of the plurality of output units; and a wave combining unit for combining the plurality of optical signals outputted from the plurality of output units and outputting the combined signal.

A communication system includes a first optical system and a second optical system optically connected to a clamping laser and a pump laser. The first optical system includes first and second optical splitters. The first optical splitter is configured to receive a clamping laser signal from the clamping laser and split the signal into split clamping laser signals. The second optical splitter is configured to receive a pump laser signal from the pump laser and split signal into split pump laser signals. The second optical system is optically connected to the first optical system and includes amplifier systems. Each amplifier system is configured to receive a multiplexed signal. The second optical system includes first and second combiners optically connected to an erbium-doped fiber. The first combiner is optically connected to the first splitter, and the second combiner is optically connected to the second splitter.

Provided is a method for reducing the impact of transient effects in an optical network. The optical network includes at least one span, and an optical signal having a plurality of sub-bands travels through at least one span of the at least one span of the optical network. Each of the at least one span has associated amplifiers and the associated amplifiers are connected to launch optical signals into a remainder of a corresponding optical transmission line. Respectively one of the sub-bands of the optical signal traveling through the span is amplified by one of these associated amplifiers. Each of the associated amplifiers includes at least one control element for controlling gain and tilt of the corresponding amplifier. The method includes the steps of for each span, acquiring an actual value of at least one performance parameter; for each span, respectively computing actual settings for each of the control elements included in the amplifiers associated to the corresponding span based on the actual value of the at least one performance parameter of the corresponding span; and for each span, respectively adjusting the settings of each of the control elements included in the amplifiers associated to the corresponding span based on the computed actual settings for the corresponding control element, in order to reduce the impact of transient effects.

An optical relay device is provided which is capable of outputting control signal light without equipping a light source for the control signal light and capable of flexibly managing and changing a wavelength of the control signal light in accordance with a state of a network. The optical relay device includes an optical receiving unit that receives a wavelength multiplexed optical signal, a control unit that specifies a first wavelength and outputting notification information, and a processing unit that selects an optical signal having the first wavelength from the received wavelength multiplexed optical signal, applying intensity-modulation in accordance with the notification information to the selected optical signal, adding the intensity-modulated optical signal back to the wavelength multiplexed optical signal, and outputting the wavelength multiplexed optical signal.

An optical relay device is provided which is capable of outputting control signal light without equipping a light source for the control signal light and capable of flexibly managing and changing a wavelength of the control signal light in accordance with a state of a network. The optical relay device includes an optical receiving unit that receives a wavelength multiplexed optical signal, a control unit that specifies a first wavelength and outputting notification information, and a processing unit that selects an optical signal having the first wavelength from the received wavelength multiplexed optical signal, applying intensity-modulation in accordance with the notification information to the selected optical signal, adding the intensity-modulated optical signal back to the wavelength multiplexed optical signal, and outputting the wavelength multiplexed optical signal.

A transmitter (TX) for a WDM optical link includes a light source (CS) generating a plurality of discrete lines (EL) with different frequencies (f), a plurality of modulators (FSM, RRM, MZM), each modulator (FSM, RRM, MZM) being configured to modulate one of the discrete lines (EL) according to a data stream (c.sub.1-c.sub.4), at least one optical amplifier (SOA) configured to simultaneously amplify multiple lines (EL), wherein only a subset of the generated lines (EL) is routed to the optical amplifier (SOA) resp. to each one of the optical amplifiers (SOA). A receiver (RX) for an optical link adapted to work together with the transmitter (TX) is also described. An optical link including the transmitter (TX) and/or the receiver (RX), and a method to operate said link are also described.

A transmitter (TX) for a WDM optical link includes a light source (CS) generating a plurality of discrete lines (EL) with different frequencies (f), a plurality of modulators (FSM, RRM, MZM), each modulator (FSM, RRM, MZM) being configured to modulate one of the discrete lines (EL) according to a data stream (c.sub.1-c.sub.4), at least one optical amplifier (SOA) configured to simultaneously amplify multiple lines (EL), wherein only a subset of the generated lines (EL) is routed to the optical amplifier (SOA) resp. to each one of the optical amplifiers (SOA). A receiver (RX) for an optical link adapted to work together with the transmitter (TX) is also described. An optical link including the transmitter (TX) and/or the receiver (RX), and a method to operate said link are also described.

An optical transmission device includes: a selector configured to select a wavelength of a signal to be transmitted to an optical transmission line and output a wavelength-multiplexed signal; an adjustor configured to control a power level of the wavelength-multiplexed signal; and a controller configured to control the adjustor or the selector, wherein the selector selects a wavelength of an optical signal in a second wavelength band different from an existing first wavelength band, and when the second wavelength band is added to or removed from the optical transmission line, the controller controls power of the wavelength-multiplexed signal in the second wavelength band at a slower speed than power control in the first wavelength band.

An optical transmission device includes: a selector configured to select a wavelength of a signal to be transmitted to an optical transmission line and output a wavelength-multiplexed signal; an adjustor configured to control a power level of the wavelength-multiplexed signal; and a controller configured to control the adjustor or the selector, wherein the selector selects a wavelength of an optical signal in a second wavelength band different from an existing first wavelength band, and when the second wavelength band is added to or removed from the optical transmission line, the controller controls power of the wavelength-multiplexed signal in the second wavelength band at a slower speed than power control in the first wavelength band.

An optical transmitter includes a dummy optical source, a polarized wave beam coupler, and an auto gain control (AGC)-system amplifier. The dummy optical source outputs, out of an optical signal in which an optical path signal and an optical packet signal are mixed, a dummy signal having a wavelength identical to that of the optical packet signal. The polarized wave beam coupler multiplexes the dummy signal with the optical signal so that the dummy signal is orthogonal to the optical signal so as to output an output signal. The AGC-system amplifier inputs the output signal, and amplifies the output signal with a predetermined amplification factor corresponding to a power difference between input power and output power of an optical amplifier.