There is provided a control device for controlling a first transmission device and a second transmission device, the control device including a memory, and a processor coupled to the memory and the processor configured to set a first wavelength path between the first transmission device and the second transmission device, select a monitoring wavelength path from established wavelength paths allocated on a transmission line between the first transmission device and the second transmission device, monitor a signal quality of the monitoring wavelength path, and increase power of the first wavelength path, based on the signal quality of the monitoring wavelength path.

The present invention discloses an optical signal frequency calibration method and device. The method includes: receiving a first optical signal that experiences a frequency offset and that is generated by a laser in a transmitter of an access node; receiving a reference optical signal sent by a local oscillator; calculating a difference between a specified frequency difference and a frequency difference between the reference optical signal and the first optical signal; and performing frequency calibration on the first optical signal according to the difference, modulating to-be-sent uplink data by using the calibrated first optical signal, and sending the modulated uplink data to a primary node.

In some embodiments, an apparatus includes a processor configured to receive a set of digital samples associated with a set of optical signals received at a coherent optical receiver. The set of digital samples is associated with a set of optical channels. Each optical channel from the set of optical channels is spaced from at least one adjacent optical channel from the plurality of optical channels. The processor is configured to calculate, for each optical channel from the set of optical channels, a spacing between that optical channel and at least one adjacent optical channel from the set of optical channels based on digital signal processing of the set of digital samples. The processor is configured to send a signal indicating, for each optical channel from the set of optical channels, the spacing between that optical channel and the at least one adjacent optical channel.

A wavelength tunable light source includes a light source, a wavelength monitor circuit configured to receive light emitted from the light source, and a processor that controls the light source based upon an output value of the wavelength monitor circuit, wherein the wavelength monitor circuit has a wavelength filter with a periodic transmission spectrum, and three photo detectors connected to outputs of the wavelength filter, and wherein the processor is configured to calculate a ratio of photo-detection normalized with two of three quantities of light received at the three photo detectors and control electric current input to the light source such that a calculated ratio of photo-detection approaches a target ratio at a designated wavelength.

An information processing apparatus, includes: a memory that stores a wavelength defragmentation program; and a processor that performs, based on the wavelength defragmentation program, operations of: selecting an optical line according to a specific sequence in design information to allocate optical lines for respective optical wavelengths within a network; moving a selected optical line to a move-to optical wavelength; stopping, when movement of the selected optical line to the move-to optical wavelength is difficult, a selection of the optical line according to the specific sequence; and selecting a new optical line from optical lines indicated in a priority list.

The present disclosure relates to a PON power meter using multi input type AWG, including a first input part into which a first signal is input, wherein the first signal has S optical signals whose wavelengths are different from each other; a second input part into which a second signal is input, wherein the second signal has P optical signals whose wavelengths are different from each other; an AWG that distributes the input signal to M output waveguides according to wavelength band; a detection part configuring (S+P) detection channels by connecting a photodetection element to only (S+P) output waveguides of the M output waveguides of the AWG; and an output part that outputs a strength of the signal detected by the detection part.

A wavelength monitoring apparatus includes a wavelength monitoring circuit. The wavelength monitoring circuit includes: a split circuit that splits an input optical signal into two; an optical delay circuit that applies a delay time difference to the two split optical signals; and a two-input two-output optical multiplexer/demultiplexer circuit that outputs a result of applying multiplexing interference to the optical signals to which the delay time difference has been applied. The wavelength monitoring apparatus further includes photoelectric conversion elements that perform photoelectric conversions on the two optical signals output from the wavelength monitoring circuit so as to output electrical signals. The wavelength monitoring apparatus is configured to obtain the wavelength of the optical signal, by calculating a ratio between two electrical outputs of the photoelectric conversion elements and referring to a correspondence table indicating wavelengths of optical signals input to the wavelength monitoring circuit and ratios between electrical outputs.

A wavelength debugging method of multi-channel optical module includes: determine the initial temperature of TEC, and plot the temperature-optical power curve of each channel; obtain temperature T.sub.up and T.sub.down corresponding to upper and lower limit values of the target wavelength of each channel and the left and right security boundary temperatures T.sub.left and T.sub.right of each channel; compare T.sub.up, T.sub.down, T.sub.left, T.sub.right of each channel, when the product is qualified, record the middle two values in descending order as T.sub.1 and T.sub.2, respectively; compare the size of T.sub.1 and T.sub.2 of each channel, when the product is qualified, take the maximum value of T.sub.1 of each channel as T.sub.down, and take the minimum value of T.sub.2 of each channel as T.sub.up, the final setting temperature of TEC is calculated as T=(T.sub.down+T.sub.up)/2, and the corresponding wavelength for each channel at this temperature T is the wavelength after debugging for each channel.

In an optical submarine cable system, the amount of work involved in setting up a terminal station device increases in association with an increase in volume. Thus, a wavelength multiplexing device according to the present invention comprises: a wavelength multiplexing means for causing input light inputted from a plurality of input ports for receiving optical signals to pass within a passband determined by a set center frequency and a set bandwidth, and outputting the light from an output port; an optical monitoring means for measuring optical power of the optical signals for each optical frequency and generating optical waveform information; a calculation means for calculating a main signal center frequency which is the center frequency of the optical signals and a main signal bandwidth which is the bandwidth of the optical signals; and a control means for setting the set center frequency to the main signal center frequency and setting the set bandwidth to the main signal bandwidth.

In some embodiments, an apparatus includes a processor configured to receive a set of digital samples associated with a set of optical signals received at a coherent optical receiver. The set of digital samples is associated with a set of optical channels. Each optical channel from the set of optical channels is spaced from at least one adjacent optical channel from the plurality of optical channels. The processor is configured to calculate, for each optical channel from the set of optical channels, a spacing between that optical channel and at least one adjacent optical channel from the set of optical channels based on digital signal processing of the set of digital samples. The processor is configured to send a signal indicating, for each optical channel from the set of optical channels, the spacing between that optical channel and the at least one adjacent optical channel.