An optical control type phased array antenna includes: a plurality of antenna elements; a multi-wavelength light source; an optical demultiplexing circuit for separating a plurality of optical signals and local oscillation light from output light of the multi-wavelength light source; optical modulators for generating a plurality of modulated optical signals by modulating the plurality of optical signals with the output signals of the plurality of antenna elements; an optical coupler for multiplexing the plurality of modulated optical signals and the local oscillation light to generate multiplexed light and dividing the multiplexed light into reception optical signals of a plurality of channels; and an optical dispersion compensation circuit for compensating for a phase difference between the plurality of modulated optical signals by performing dispersion compensation on the reception optical signals, respectively.

There is provided an OTDR method and device for characterizing an optical fiber link. At least a first OTDR acquisition is performed toward the optical fiber link. From the at least one first OTDR acquisition, one or more events are identified along the optical fiber link and a value of at least one characteristic associated with each event is estimated. A second OTDR acquisition is performed toward the optical fiber link in order to target a specific event among the identified events. Values of one or more OTDR acquisition parameters for the second OTDR acquisition are determined such that the OTDR acquisition parameters comprise a second pulse width different from the first pulse width used in the first OTDR acquisition.

An optical control type phased array antenna includes: a plurality of antenna elements; a multi-wavelength light source; an optical demultiplexing circuit for separating a plurality of optical signals and local oscillation light from output light of the multi-wavelength light source; optical modulators for generating a plurality of modulated optical signals by modulating the plurality of optical signals with the output signals of the plurality of antenna elements; an optical coupler for multiplexing the plurality of modulated optical signals and the local oscillation light to generate multiplexed light and dividing the multiplexed light into reception optical signals of a plurality of channels; and an optical dispersion compensation circuit for compensating for a phase difference between the plurality of modulated optical signals by performing dispersion compensation on the reception optical signals, respectively.

There is provided an OTDR method and device for characterizing an optical fiber link. At least a first OTDR acquisition is performed toward the optical fiber link. From the at least one first OTDR acquisition, one or more events are identified along the optical fiber link and a value of at least one characteristic associated with each event is estimated. A second OTDR acquisition is performed toward the optical fiber link in order to target a specific event among the identified events. Values of one or more OTDR acquisition parameters for the second OTDR acquisition are determined such that the OTDR acquisition parameters comprise a second pulse width different from the first pulse width used in the first OTDR acquisition.

A transmission apparatus includes a demultiplexer configured to demultiplex a multiplexed signal including wavelength multiplexed signals having individual wavelength bands into a wavelength multiplexed signal for each of the wavelength bands, a detector configured to detect a power value of each of the wavelength multiplexed signals for each of the wavelength bands, first compensators configured to compensate for a tilt in the wavelength multiplexed signal based on the power value for each of the wavelength bands, second compensators configured to compensate for a power of the wavelength multiplexed signal for each of the wavelength bands so as to reduce a power difference among wavelength multiplexed signals after the tilt compensation based on the power value for each of the wavelength bands, and a multiplexer configured to multiplex each of the wavelength multiplexed signals after the power compensation and output a multiplexed signal.

A transmission apparatus includes a demultiplexer configured to demultiplex a multiplexed signal including wavelength multiplexed signals having individual wavelength bands into a wavelength multiplexed signal for each of the wavelength bands, a detector configured to detect a power value of each of the wavelength multiplexed signals for each of the wavelength bands, first compensators configured to compensate for a tilt in the wavelength multiplexed signal based on the power value for each of the wavelength bands, second compensators configured to compensate for a power of the wavelength multiplexed signal for each of the wavelength bands so as to reduce a power difference among wavelength multiplexed signals after the tilt compensation based on the power value for each of the wavelength bands, and a multiplexer configured to multiplex each of the wavelength multiplexed signals after the power compensation and output a multiplexed signal.

Wavelength multiplexed optical communication systems include a channeled chromatic dispersion compensator coupled to receive modulated optical beams associated with a plurality of optical channels at respective communication wavelengths. The channeled chromatic dispersion compensator applies independently selected dispersion compensations to each of the optical channels by identifying a dispersion compensation associated with a preferred bit error rate, inter-symbol interference, or other signal quality metric, or determined using optical fiber properties such as dispersion slope and zero dispersion wavelength. Chromatic dispersion compensation can be coupled with channel power equalization, and can be performed at a receiver or a transmitter or in the middle of a fiber span.

A method for overlapping spectrum amplification includes receiving an optical signal and splitting the optical signal into a first split signal having a first wavelength band and a second split signal having a second wavelength band. The splitting results in a band gap between the first wavelength band and the second wavelength band. The method further includes delaying the first split signal by a threshold period of time relative to the second split signal and combining the first split signal and the second split signal, resulting in a combined signal having the first wavelength band and the second wavelength band without the band gap therebetween. The path difference between the first split signal along the first signal path and the second split signal along the second signal path is within a threshold multipath interference compensation range.

A method for overlapping spectrum amplification includes receiving an optical signal and splitting the optical signal into a first split signal having a first wavelength band and a second split signal having a second wavelength band. The splitting results in a band gap between the first wavelength band and the second wavelength band. The method further includes delaying the first split signal by a threshold period of time relative to the second split signal and combining the first split signal and the second split signal, resulting in a combined signal having the first wavelength band and the second wavelength band without the band gap therebetween. The path difference between the first split signal along the first signal path and the second split signal along the second signal path is within a threshold multipath interference compensation range.