The present disclosure provides example method for sending a signal in optical communication, an example optical transmitter, and an example optical communication system. One example method for sending a signal in optical communication includes generating, by an optical transmitter, multiple first subcarriers based on a bit stream. State of polarization (SOP) rotation is performed by the optical transmitter on at least one subcarrier in the multiple first subcarriers to generate multiple second subcarriers, wherein the multiple second subcarriers comprise multiple subcarriers each with a relative SOP rotation angle, and the relative SOP rotation angle is not zero and is not an integer multiple of 90 degrees. The multiple second subcarriers are modulated to an optical signal. The modulated optical signal is sent by the optical transmitter.

The present disclosure provides example method for sending a signal in optical communication, an example optical transmitter, and an example optical communication system. One example method for sending a signal in optical communication includes generating, by an optical transmitter, multiple first subcarriers based on a bit stream. State of polarization (SOP) rotation is performed by the optical transmitter on at least one subcarrier in the multiple first subcarriers to generate multiple second subcarriers, wherein the multiple second subcarriers comprise multiple subcarriers each with a relative SOP rotation angle, and the relative SOP rotation angle is not zero and is not an integer multiple of 90 degrees. The multiple second subcarriers are modulated to an optical signal. The modulated optical signal is sent by the optical transmitter.

A polarization-dependent loss (PDL) determining method includes obtaining two groups of optical powers within first duration, selecting at least one group of target optical powers that satisfy a same power constraint from the two groups of optical powers, where each group of target optical powers includes a first target power and a second target power from the two groups of optical powers, and determining a PDL of the optical device based on the at least one group of target optical powers.

A polarization-dependent loss (PDL) determining method includes obtaining two groups of optical powers within first duration, selecting at least one group of target optical powers that satisfy a same power constraint from the two groups of optical powers, where each group of target optical powers includes a first target power and a second target power from the two groups of optical powers, and determining a PDL of the optical device based on the at least one group of target optical powers.

Aspects of the present disclosure describe distributed fiber optic sensing (DFOS) systems, methods, and structures that advantageously achieve single mode fiber distributed temperature sensing (DTS) with improved noise characteristics by employing a polarization scrambler in its optical chain.

Aspects of the present disclosure describe distributed fiber optic sensing (DFOS) systems, methods, and structures that advantageously achieve single mode fiber distributed temperature sensing (DTS) with improved noise characteristics by employing a polarization scrambler in its optical chain.

A device (10;150;200) is configured to receive an optical signal. The device comprises a dispersion compensator (210a) comprising a plurality of optical dispersion compensator units (220). Each optical dispersion compensator unit comprises a plurality of delay elements (20;40). The dispersion compensator (210a) is configured to selectively activate one or more of the optical dispersion compensator units (220). The dispersion compensator (210a) is configured to compensate for dispersion of the optical signal with the activated one or more optical dispersion compensator unit (200).

A device (10;150;200) is configured to receive an optical signal. The device comprises a dispersion compensator (210a) comprising a plurality of optical dispersion compensator units (220). Each optical dispersion compensator unit comprises a plurality of delay elements (20;40). The dispersion compensator (210a) is configured to selectively activate one or more of the optical dispersion compensator units (220). The dispersion compensator (210a) is configured to compensate for dispersion of the optical signal with the activated one or more optical dispersion compensator unit (200).

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.