A multi-level optical signal is sampled to generate an eye diagram. The signal can be adjusted when eyes in the eye diagram have different heights. More specifically, a first value is determined, and the height of a first eye is adjusted using the first value. The first value is multiplied by a stored factor to produce a second value, and the height of a second eye is adjusted using the second value, and so on for other eyes. As a result, eye heights are the same. Similarly, optical power levels of the signal can be adjusted when the levels are not equally spaced. As a result, the optical power levels are equally spaced.

Provided are an alarm processing method and apparatus for an optical transport network, a network management system and a non-transitory computer readable storage medium. The alarm processing method for an optical transport network may include: acquiring intra-layer alarms of respective layers of a service layer by layer; acquiring a root alarm of an associated layer corresponding to a current layer based on the intra-layer alarms; and determining a service fault point based on the root alarm.

Methods for configuring an optical link in which a distribution of transmission data rates and line rates are configured for a predetermined amount of optical bandwidth to maximize transmission capacity. In these methods, a controller of an optical network obtains input parameters that include a signal-to-noise ratio (SNR) for optical signals and an allocated bandwidth of the optical link, further obtains, for each line rate, a mapping of transmission data rates along a frequency spectrum of the allocated bandwidth compatible with the SNR, and generates a channel plan in which a number of traffic modes and a distribution of a plurality of channels in the allocated bandwidth are set to maximize transmission capacity. The plurality of channels is used for transmitting the signals on the optical link. The controller configures at least one optical network element in the optical network to establish the optical link based on the channel plan.

An optical communication equipment performs optical communication between a first apparatus and a second apparatus. The optical communication equipment includes a monitoring section configured to monitor a light amount during optical communication, and a control device configured to output predetermined information when the light amount is less than a first threshold value and shut off communication between the first and second apparatuses when the light amount is less than a second threshold value lower than the first threshold value.

Disclosed herein is a transponder comprising a transmitter and a receiver. The transponder further comprises a receiver input amplifier, a bypass line, and a control unit configured for determining the performance of the transponder in relation to an OSNR related parameter, by controlling the transponder to generate a noise signal to be received by the receiver. The receiver input amplifier is operated to thereby cause ASE in the receiver input amplifier to facilitate the determination. A test signal is generated at the transmitter Said noise signal and said test signal, and/or one or more respective replicas thereof, are superimposed to form a combined signal to be received by said receiver to further facilitate determination of said performance related parameter based on said combined signal, wherein for generating said combined signal, said test signal is fed from the transmitter to the receiver by means of said bypass line.

An optical transmitter includes: a modulator, square law detector, and a processor. The modulator generates an optical signal indicating transmission data. The square law detector detects an intensity of the optical signal using a photodetector and output first intensity data indicating the detected intensity. The processor calculates, based on the transmission data, an electric field of the optical signal generated by the modulator by using parameters pertaining to a state of the modulator. The processor calculates second intensity data indicating the intensity of the optical signal based on the calculated electric field. The processor updates the parameters so as to reduce a difference between the first intensity data and the second intensity data. The processor controls the state of the modulator based on the parameters.

The present invention discloses an intelligent real-time full-field measurement method and system for a high-repetition-rate femtosecond pulse. The method includes: splitting a to-be-tested signal into n channels; performing a frequency reduction separation on each of the channels; splitting each channel of frequency-reduced time-domain demultiplexed signals into two signals, where a small dispersion component performs time-domain stretching on one signal, and a big dispersion component performs a time-frequency conversion on the other signal; acquiring time-domain intensity information of the to-be-tested signal after the stretching by the small dispersion component and frequency-domain envelope information of the to-be-tested signal after the time-frequency conversion by the big dispersion component; and continuously iterating the acquired time-domain intensity information and frequency-domain envelope information according to a Gerchberg-Saxton algorithm until a convergence is achieved, to obtain information about intensity and phase of the to-be-tested signal in a time domain and a frequency domain.

The present invention discloses an intelligent real-time full-field measurement method and system for a high-repetition-rate femtosecond pulse. The method includes: splitting a to-be-tested signal into n channels; performing a frequency reduction separation on each of the channels; splitting each channel of frequency-reduced time-domain demultiplexed signals into two signals, where a small dispersion component performs time-domain stretching on one signal, and a big dispersion component performs a time-frequency conversion on the other signal; acquiring time-domain intensity information of the to-be-tested signal after the stretching by the small dispersion component and frequency-domain envelope information of the to-be-tested signal after the time-frequency conversion by the big dispersion component; and continuously iterating the acquired time-domain intensity information and frequency-domain envelope information according to a Gerchberg-Saxton algorithm until a convergence is achieved, to obtain information about intensity and phase of the to-be-tested signal in a time domain and a frequency domain.

Techniques for maintaining equipment of a PON include determining a current optical profile for each segment of a plurality of segments of a PON, and detecting that the current optical profile of a particular segment is outside of a designated operating range. Based on the detection, drifts over time of the optical profile of the segment and of optical profiles of one or more other segments that share respective common endpoints with the segment are determined and compared, and based on the comparison, a component of the PON (e.g., an endpoint or an optical fiber) is identified as requiring maintenance. Each segment's optical profile corresponds to characteristics of optical signals delivered over the segment (e.g., attenuation, changes in frequencies, changes in power outputs, etc.), and current optical profiles of the PON's segments may be repeatedly updated over time to continuously monitor for components that need maintenance.

The present disclosure intends to provide an optical signal from an ONU according to a desired service usage state without using the ONU and an OLT. A simulated signal light generation apparatus 10 according to the present disclosure is a simulated signal light generation apparatus 10 for simulating an uplink signal light generated in an optical network unit (ONU) in a passive optical network (PON), and the apparatus includes a usage state control unit 11 that sets a service usage state of the ONU, a signal generation unit 12 that generates an uplink signal frame according to the usage state set by the usage state control unit 11, and an electrical/optical conversion unit 13 that converts an electrical signal from the signal generation unit 12 into an optical signal, and the optical signal from the electrical/optical conversion unit 13 is repeatedly transmitted to an optical fiber core 22.