The present disclosure provides signal management with unequal eye spacing by: determining a dispersion slope of a channel between a transmitter and a receiver based on a temperature of the transmitter and a wavelength used by the transmitter to transmit signals over the channel; determining maximum and minimum powers for transmission over the channel; assigning a plurality of rails to a corresponding plurality of power levels, wherein amplitude differences between adjacent rails of the plurality of rails are based on the dispersion slope and produce a first eye pattern with a first Ratio of Level Mismatch (RLM) less than one; encoding, by the transmitter, data onto a conditioned signal according to the plurality of rails; and transmitting the conditioned signal over the channel, so that the conditioned signal demonstrates a second eye pattern with a second RLM greater than the first RLM when received at the receiver.

The present disclosure provides signal management with unequal eye spacing by: determining a dispersion slope of a channel between a transmitter and a receiver based on a temperature of the transmitter and a wavelength used by the transmitter to transmit signals over the channel; determining maximum and minimum powers for transmission over the channel; assigning a plurality of rails to a corresponding plurality of power levels, wherein amplitude differences between adjacent rails of the plurality of rails are based on the dispersion slope and produce a first eye pattern with a first Ratio of Level Mismatch (RLM) less than one; encoding, by the transmitter, data onto a conditioned signal according to the plurality of rails; and transmitting the conditioned signal over the channel, so that the conditioned signal demonstrates a second eye pattern with a second RLM greater than the first RLM when received at the receiver.

Communication of light signals and optical cables can be managed to mitigate error associated with using optical cables to communicate light signals. A communication management component (CMC) can embed respective timing synchronization pulses in respective lights signals having respective wavelengths. The light signals can be typical light signals or can be squeezed and twisted to generate a desired twisted light signal. The light signals can be transmitted via the optical cable to a receiver. A CMC, at the receiver end, can determine error associated with the transmission of the light signals via the optical cable and respective characteristics of the respective light signals, including respective arrival times of the respective timing synchronization pulses and respective light intensity or power levels of the respective light signals. From the respective characteristics, CMC can determine a compensation action to perform mitigate the error with regard to subsequent transmissions of light signals.

Communication of light signals and optical cables can be managed to mitigate error associated with using optical cables to communicate light signals. A communication management component (CMC) can embed respective timing synchronization pulses in respective lights signals having respective wavelengths. The light signals can be typical light signals or can be squeezed and twisted to generate a desired twisted light signal. The light signals can be transmitted via the optical cable to a receiver. A CMC, at the receiver end, can determine error associated with the transmission of the light signals via the optical cable and respective characteristics of the respective light signals, including respective arrival times of the respective timing synchronization pulses and respective light intensity or power levels of the respective light signals. From the respective characteristics, CMC can determine a compensation action to perform mitigate the error with regard to subsequent transmissions of light signals.

Methods, systems, and apparatus, including computer programs encoded on computer storage media, for clock recovery in subcarrier based coherent optical systems. In one aspect, an apparatus includes a plurality of phase detectors configured to generate a plurality of phase detection outputs by detecting a plurality of digital signals associated with a plurality of frequency bands, each of the plurality of phase detection outputs being associated with a respective one of the plurality of frequency bands, alignment circuitry coupled to the plurality of phase detectors and configured to align phases of the plurality of phase detection outputs to be substantially same, and averaging circuitry coupled to the alignment circuitry and configured to generate a particular output based on the plurality of phase detection outputs with the aligned phases. The plurality of digital signals is adjusted based on the particular output.

Methods, systems, and apparatus, including computer programs encoded on computer storage media, for clock recovery in subcarrier based coherent optical systems. In one aspect, an apparatus includes a plurality of phase detectors configured to generate a plurality of phase detection outputs by detecting a plurality of digital signals associated with a plurality of frequency bands, each of the plurality of phase detection outputs being associated with a respective one of the plurality of frequency bands, alignment circuitry coupled to the plurality of phase detectors and configured to align phases of the plurality of phase detection outputs to be substantially same, and averaging circuitry coupled to the alignment circuitry and configured to generate a particular output based on the plurality of phase detection outputs with the aligned phases. The plurality of digital signals is adjusted based on the particular output.

A reception apparatus includes a dispersion compensation unit configured to acquire an electrical signal resulting from conversion of an optical signal and perform, on the electrical signal, dispersion compensation with a predetermined compensation amount, a clip rate measurement unit configured to measure a clip rate for the electrical signal subjected to the dispersion compensation, and a control unit configured to detect the compensation amount that minimizes the clip rate.

A reception apparatus includes a dispersion compensation unit configured to acquire an electrical signal resulting from conversion of an optical signal and perform, on the electrical signal, dispersion compensation with a predetermined compensation amount, a clip rate measurement unit configured to measure a clip rate for the electrical signal subjected to the dispersion compensation, and a control unit configured to detect the compensation amount that minimizes the clip rate.

An optical transmission/reception unit includes a carrier rotatable about a rotational axis, an optical receiver arranged at the carrier on the rotational axis to receive an optical reception signal from a first direction, an optical transmitter arranged adjacent to the optical receiver at the carrier to emit an optical transmission signal in a second direction, and a transmission/reception optic arranged at the carrier on the rotational axis above the optical receiver and extending across the optical receiver and the optical transmitter, wherein the transmission/reception optic includes a reception optic and a transmission optic arranged in the reception optic. The reception optic is configured to guide the optical reception signal incident on the transmission/reception optic towards the optical receiver on the rotational axis, and the transmission optic is arranged above the optical transmitter and is configured to shape the optical transmission signal emitted by the optical transmitter into an output beam.

Cost-effective high-data-rate optical data transceivers are presented, comprising an electronic analog transversal filter simultaneously providing one or more of bandwidth compensation and forward impairment compensations for the transmitted optical signal.