A signal light interruption detection device includes an optical interleaver to demultiplex wavelength-multiplexed light into light in first frequency ranges corresponding to a first frequency grid including frequencies at regular frequency intervals in which a main signal light component can be arranged and light in second frequency ranges corresponding to a second frequency grid shifted from the first frequency grid by a half cycle of the regular frequency intervals, a first optical detector to detect first light power as total power of the light in the first frequency ranges, a second optical detector to detect second light power as total power of the light in the second frequency ranges, and a judgment unit to output a notification signal based on a difference between the first light power detected by the first optical detector and the second light power detected by the second optical detector.

A signal light interruption detection device includes an optical interleaver to demultiplex wavelength-multiplexed light into light in first frequency ranges corresponding to a first frequency grid including frequencies at regular frequency intervals in which a main signal light component can be arranged and light in second frequency ranges corresponding to a second frequency grid shifted from the first frequency grid by a half cycle of the regular frequency intervals, a first optical detector to detect first light power as total power of the light in the first frequency ranges, a second optical detector to detect second light power as total power of the light in the second frequency ranges, and a judgment unit to output a notification signal based on a difference between the first light power detected by the first optical detector and the second light power detected by the second optical detector.

Disclosed is a method of Controlling a gain of an optical amplifier comprising a gain medium and at least one pumping device. The method comprises the following steps: determining or predicting a change of input signal power to the amplifier, changing the pump power from an initial pump power level to a new pump power level at a first time instant, the initial pump power level being the pump power level applied to the amplifier prior to the change in input signal power, setting the pump power to a second pump power level at a second time instant, wherein the pump power level is varied in an oscillatory manner for at least one period of time starting at a third time instant and ending at a fourth time instant, wherein said third time instant is identical with or later than said first time instant and said fourth time instant is identical with or earlier than said second time instant.

Disclosed is a method of Controlling a gain of an optical amplifier comprising a gain medium and at least one pumping device. The method comprises the following steps: determining or predicting a change of input signal power to the amplifier, changing the pump power from an initial pump power level to a new pump power level at a first time instant, the initial pump power level being the pump power level applied to the amplifier prior to the change in input signal power, setting the pump power to a second pump power level at a second time instant, wherein the pump power level is varied in an oscillatory manner for at least one period of time starting at a third time instant and ending at a fourth time instant, wherein said third time instant is identical with or later than said first time instant and said fourth time instant is identical with or earlier than said second time instant.

In some examples, an optical node includes transition logic to: receive an indication of a data channel to be added across an optical medium, the data channel to occupy a portion of an optical spectrum; in response to a receipt of the indication, divide the data channel into a plurality of sub-channels; and sequentially add each of the plurality of sub-channels across the optical medium in a particular order.

A method, implemented in an optical line system, includes monitoring traffic channels of a plurality of traffic channels; determining one or more traffic channels of the plurality of traffic channels are problematic with respect to other traffic channels of the plurality of traffic channels; and squelching the one or more traffic channels and replacing the squelched one or more traffic channels with channel holders. The method can further include continuing the monitoring of the squelched one or more traffic channels; determining the squelched one or more traffic channels are no longer problematic; and re-adding the squelched one or more traffic channels by replacing the channel holders therewith.

A method is described in which a database is monitored. The database includes information specifying allocations of time periods in which a first optical carrier corresponding to a first optical channel will not be supplying encoded first data into output optical signals being transmitted from a first node to a second node. An idler carrier being amplified stimulated emission light having a frequency corresponding to the first optical channel is supplied into the output optical signals transmitted from the first node to the second node during the time periods in which the first optical carrier will not be supplying encoded first data into the output optical signals.

A method is described in which a loss of spectrum in an optical signal having an optical signal spectrum is detected. The optical signal is transmitted from a first node to a second node. In response to detecting the loss of spectrum in the optical signal, at least one idler carrier without data imposed is supplied into the optical signal spectrum transmitted from the first node to the second node, the optical signal spectrum encompassing a frequency band including a plurality of optical channels, the idler carrier being amplified stimulated emission light having a frequency corresponding to a first optical channel of the plurality of optical channels.

An example system includes a first data port and a second data port. The system includes a controller electrically coupled to the first and second data ports. The controller is to cause the first data port to receive power. The controller is to cause the second data port to output at least a portion of the received power. The controller is to detect an impending loss of power to the first data port. The controller is to cause the second data port to transmit an urgent power request.

[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.