Implementing a laser into a system that uses a remote powered combiner or an aggregating combiner (AC) with one or more in-range contributing combiners may provide power to the downstream contributing combiners (CC). The power may be provided on the same fiber that downstream signals and the upstream signals traverse.

A device may perform a set of sample measurements of a set of slices of spectrum utilized by an input optical signal. The device may perform an analysis of the input optical signal to determine an attenuation profile. The analysis may include identifying a channel in a particular slice of spectrum, of the set of slices of spectrum, based on an optical power of a sample measurement, of the set of sample measurements, satisfying a threshold. The device may apply the attenuation profile to the input optical signal to generate an output optical signal with a particular spectral shape. The device may provide the output optical signal with the particular spectral shape.

A variable equalizer, a repeater, and an equalizing method capable of reducing a cost incurred due to a plurality of equalizers which would otherwise need to be prepared according to the use conditions of the amplifier are provided. A variable equalizer includes an analysis unit configured to analyze a first spectrum of a wavelength-division multiplexed optical signal amplified by an amplifier, a control unit configured to calculate a loss profile indicating a loss for each wavelength based on the first spectrum so that a second spectrum of the wavelength-division multiplexed optical signal to which the loss profile is added becomes flat, and a WSS (Wavelength Selective Switch) configured to add the loss profile to the wavelength-division multiplexed optical signal.

The optical amplifier, which amplifies wavelength multiplexed signal light, comprises: a multi-core optical fiber which includes cladding and a first core and a second core disposed in the cladding, and which is doped with rare-earth ions; an excitation light source for supplying excitation light to the cladding of the multi-core optical fiber; and a wavelength demultiplexing means for separating the wavelength bands of the wavelength multiplexed signal light that has propagated through the first core. The signal light of a relatively long wavelength band among a plurality of wavelength bands separated by the wavelength demultiplexing means is caused to propagate through the second core, and is then multiplexed with the signal light of a relatively short wavelength band among the plurality of wavelength bands separated by the wavelength demultiplexing means, and the resultant multiplexed signal light is output.

An optical amplifier that amplifies an incident WDM signal and includes cores having an amplification medium, the optical amplifier includes: a wavelength demultiplexer configured to demultiplex the incident WDM signal into wavelength bands and introducing the demultiplexed WDM signals into the cores separately; a wavelength multiplexer configured to multiplex amplified optical signals propagated through the cores and outputting the multiplexed signal; and an wavelength demultiplexing controller configured to monitor an amplification rate of a specific wavelength band of an amplified WDM signal or a scale associated with an amplification rate of a specific wavelength band, demultiplexing, from the incident WDM signal, an optical signal of a wavelength band having relatively-small optical amplification efficiency according to a monitoring result, and controlling demultiplexing performed by the wavelength demultiplexer in such a way as to amplify, with a relatively-large amplification rate, the optical signal of the wavelength band having relatively-small optical amplification efficiency.

An apparatus includes an optical power supply including: a power supply light source configured to generate power supply light; at least one optical input/output port; at least one photodetector; and a coupling module. The coupling module is configured to receive the power supply light from the power supply light source and output the power supply light through the optical input/output port, receive reflected light through the optical input/output port, and transmit the reflected light to the photodetector. The photodetector is configured to detect the reflected light and generate a signal representing a level of the reflected light. The optical power supply includes a controller that is configured to compare the level of the detected reflected light with a threshold value, and upon determining that the level of the detected reflected light is less than the threshold value, reduce or turn off the power supply light that is provided to the optical input/output port.

The likelihood that a signal waveform is a Fabry-Perot signal is determined using features belonging the signal waveform. Features include a periodic peak difference likelihood and a gain profile likelihood. A spectrum snapshot of a signal waveform is captured for an optical fiber spectrum to obtain a power spectral density. A plurality of peaks is identified within the signal waveform of the spectrum snapshot. A periodic peak difference likelihood function is executed to determine a first likelihood value that the plurality of peaks is periodic. A gain profile likelihood estimator function is executed to determine a second likelihood value that the signal waveform has symmetrically decreasing peaks from center peak of the plurality of peaks. The first likelihood value and the second likelihood value are combined to determine a total likelihood value. Based on the total likelihood value, a Fabry-Perot signal is determined for the signal waveform.

A multiplexer module and method are herein disclosed. The multiplexer module comprises a WSS configured to receive a plurality of first optical signals, selectively multiplex the first optical signals into a second optical signal, and output the second optical signal; an OPM operable to determine a power of one or more slice within a sample optical signal, the sample optical signal being selected from a group consisting of a particular optical signal of the first optical signals and a portion of the second optical signal including the particular optical signal; a processor; and a memory storing instructions that cause the processor to: validate the particular optical signal using the power of one or more slice within the sample optical signal; and if the particular optical signal is valid, cause the WSS to open a particular passband so as to multiplex the particular optical signal into the second optical signal.

An optical add/drop multiplexer includes: a first wavelength selector configured to output an optical signal of each wavelength of an inputted first wavelength multiplexed signal while selecting a path for each wavelength; a measurement circuit configured to measure optical power of an inputted optical signal; and a second wavelength selector including a circuit configured to output an optical signal of each wavelength of the first wavelength multiplexed signal while selecting a path for each wavelength, in place of the first wavelength selector when an abnormality occurs in the first wavelength selector, and a circuit configured to output an inputted second wavelength multiplexed signal for each prescribed wavelength unit to the measurement circuit when the first wavelength selector normally operates.

To provide an optical transport device that enable the strengths of optical signals to be recovered when the strengths of the optical signals vary, an optical transmission device comprises: a wavelength selection switch that attenuates, in accordance with an attenuation amount, each of a plurality of optical signals outputted from a plurality of optical transmitter, multiplexes and outputs the attenuated optical signals; and an optical detector that detects and compares the strength of at least one of the plurality of optical signals with a first threshold value and a second threshold value higher than the first threshold value. On the basis of the result of said comparison, the wavelength selection switch controls the attenuation amount such that the optical signal the strength of which has been detected has a strength value between the first threshold value and the second threshold value.