Abstract: In some aspects, the disclosure is directed to methods and systems for improving signal to noise ratios of signals from multiple communication links. In some embodiments, a system includes a first frequency transformation circuit configured to transform a first signal in a time domain received from a first device into a corresponding second signal in a frequency domain. The system further includes a second frequency transformation circuit configured to transform a third signal in the time domain received from a second device into a corresponding fourth signal in the frequency domain. The system further includes a leg combining circuit configured to select, for a group of subcarriers, one of the first frequency transformation circuit and the second frequency transformation circuit, and cause, for the group of subcarriers, the selected frequency transformation circuit to output one of the second signal and the fourth signal, according to the selection.

Abstract: An architecture for combining full-duplex and frequency division duplex communication systems, includes a coupler coupled to a terminal and configured to allow duplex transmissions of digital signals via the terminal. The subject architecture includes a filtering device coupled to the coupler and configured to divide a downstream signal received through the coupler into a plurality of downstream signals associated with a plurality of frequency ranges. The subject architecture includes a transmitter coupled to the coupler and configured to drive, through the coupler, an upstream signal comprising digital signals associated with the plurality of frequency ranges. The subject architecture also includes a plurality of receivers coupled to the filtering device and configured to receive respective ones of the plurality of downstream signals.

Abstract: System for coupling light to integrated devices, comprising a grating coupler which couples light, such as light from a light source, into an optic fiber. The system includes an optic subsystem comprising a transmitter portion receiving the light emitted by the grating coupler and a receiver portion receiving light from the transmitter and focusing the light into the integrated device, the transmitter portion being configured to modify an angle distribution of the light emitted by the grating coupler and the receiving portion being configured to focus the light with modified angle distribution into the integrated device.

Abstract: In some aspects, the disclosure is directed to methods and systems for improving signal to noise ratios of signals from multiple communication links. In some embodiments, a system includes a first frequency transformation circuit configured to transform a first signal in a time domain received from a first device into a corresponding second signal in a frequency domain. The system further includes a second frequency transformation circuit configured to transform a third signal in the time domain received from a second device into a corresponding fourth signal in the frequency domain. The system further includes a leg combining circuit configured to select, for a group of subcarriers, one of the first frequency transformation circuit and the second frequency transformation circuit, and cause, for the group of subcarriers, the selected frequency transformation circuit to output one of the second signal and the fourth signal, according to the selection.

Abstract: The invention relates to a folded Mach-Zehnder modulator. The modulator may comprise a beam splitter configured to split an input light beam into a plurality of light beams. The modulator may comprise a plurality of Mach-Zehnder devices configured to receive one or more of the plurality of light beams. The modulator may comprise a U-turn section configured to receive light beams from the Mach-Zehnder devices and to change the direction of the light beams by substantially 180 degrees. The modulator may comprise a polarization management section configured to combine light beams received from the U-turn section and to output a polarization multiplexed phase modulated light beam.

Abstract: Systems and methods relate to providing a transmit signal. The transmit signal can be provided in a transmitter circuit including a main pre-equalizer, a main power amplifier in communication with the main pre-equalizer, a replica pre-equalizer, and a replica power amplifier in communication with the replica pre-equalizer. The replica preamplifier is in communication with the main pre-equalizer, and control signals are provided to the main pre-equalizer to reduce distortion. The control signals are provided in response to an output signal of the replica power amplifier.

Abstract: Systems and methods relate to providing a transmit signal. The transmit signal can be provided in a transmitter circuit including a main pre-equalizer, a main power amplifier in communication with the main pre-equalizer, a replica pre-equalizer, and a replica power amplifier in communication with the replica pre-equalizer. The replica preamplifier is in communication with the main pre-equalizer, and control signals are provided to the main pre-equalizer to reduce distortion. The control signals are provided in response to an output signal of the replica power amplifier.

Abstract: A method and apparatus is disclosed to couple a transmission amplifier and a reception amplifier to a shared medium. An output of the transmission amplifier is directly coupled to an input of the reception amplifier to form a common connection. The transmission amplifier and the reception amplifier may receive a first amplifier bias via the common connection. In response to the first amplifier bias, the transmission amplifier provides a first communication signal to the shared medium and the reception amplifier does not provide a second communication signal from the shared medium. Alternatively, the transmission amplifier and the reception may receive a second amplifier bias via the common connection. In response to the second amplifier bias, the reception amplifier provides the second communication signal from the shared medium and the transmission amplifier does not provide the first communication signal to the shared medium.

Abstract: System for coupling light to integrated devices, comprising a grating coupler which couples light, such as light from a light source, into an optic fiber. The system includes an optic subsystem comprising a transmitter portion receiving the light emitted by the grating coupler and a receiver portion receiving light from the transmitter and focusing the light into the integrated device, the transmitter portion being configured to modify an angle distribution of the light emitted by the grating coupler and the receiving portion being configured to focus the light with modified angle distribution into the integrated device.

Abstract: A system includes a weighting element, a transconductance circuit, a feedback loop, and an auxiliary loop. In some implementations, the transconductance circuit may accept an input and provide a first portion of an output for amplification at a variable amplification level to generate an amplifier output. The feedback loop may provide a portion of the amplifier output as a first feedback to the input. The first feedback may be associated with an impedance that may vary with the amplification level. The auxiliary loop may provide a second feedback to the input to reduce the dependence of the impedance on the amplification level.

Abstract: The invention relates to a folded Mach-Zehnder modulator. The modulator may comprise a beam splitter configured to split an input light beam into a plurality of light beams. The modulator may comprise a plurality of Mach-Zehnder devices configured to receive one or more of the plurality of light beams. The modulator may comprise a U-turn section configured to receive light beams from the Mach-Zehnder devices and to change the direction of the light beams by substantially 180 degrees. The modulator may comprise a polarisation management section configured to combine light beams received from the U-turn section and to output a polarisation multiplexed phase modulated light beam.

Abstract: Various multi-lane ADCs are disclosed that substantially compensate for impairments present within various signals that result from various impairments, such as phase offset, amplitude offset, and/or DC offset to provide some examples, such that their respective digital output samples accurately represent their respective analog inputs. Generally, the various multi-lane ADCs determine various statistical relationships, such as various correlations to provide an example, between these various signals and various known calibration signals to quantify the phase offset, amplitude offset, and/or DC offset that may be present within the various signals. The various multi-lane ADCs adjust the various signals to substantially compensate for the phase offset, amplitude offset, and/or DC offset based upon these various statistical relationships such that their respective digital output samples accurately represent their respective analog inputs.

Abstract: Systems and methods for demodulating a plurality of contiguous channels contained within a bandlimited portion of a radio-frequency (RF) input signal are provided. In an embodiment, the bandlimited portion of the RF input signal is down-converted to baseband. After down-conversion, the bandlimited portion overlaps at baseband with a mirror image of the bandlimited portion. The plurality of contiguous channels within the down-converted signal similarly overlap at baseband and subsequently occupy a bandwidth substantially equal to half that required before down-converting. Image rejection is performed in the digital domain to recover each of the plurality of overlapping channels.

Abstract: A system includes a weighting element, a transconductance circuit, a feedback loop, and an auxiliary loop. In some implementations, the transconductance circuit may accept an input and provide a first portion of an output for amplification at a variable amplification level to generate an amplifier output. The feedback loop may provide a portion of the amplifier output as a first feedback to the input. The first feedback may be associated with an impedance that may vary with the amplification level. The auxiliary loop may provide a second feedback to the input to reduce the dependence of the impedance on the amplification level.

Abstract: A photonic assembly is described. The assembly comprises a substrate. An optical modulator (100) in or on the substrate has an output port coupled to an output waveguide (106) mounted in or on the substrate. A spiller waveguide (107, 108) is mounted in or on the substrate. The spiller waveguide (107, 108) has an input end (109, 110) physically separated from but proximate to the output waveguide (106) so as to collect light spilt from the output port or output waveguide (106). The modulator (106) may be a MZI modulator.

Abstract: A system comprises a first amplifier stage including a first amplifier, a second amplifier stage including second and third amplifiers, and a fourth amplifier. The first amplifier stage includes an input and an output. The second amplifier stage is coupled between the output of the first amplifier stage and a first output node. The fourth amplifier is coupled between the input of the first amplifier stage and a second output node.

Abstract: Various multi-lane ADCs are disclosed that substantially compensate for impairments present within various signals that result from various impairments, such as phase offset, amplitude offset, and/or DC offset to provide some examples, such that their respective digital output samples accurately represent their respective analog inputs. Generally, the various multi-lane ADCs determine various statistical relationships, such as various correlations to provide an example, between these various signals and various known calibration signals to quantify the phase offset, amplitude offset, and/or DC offset that may be present within the various signals. The various multi-lane ADCs adjust the various signals to substantially compensate for the phase offset, amplitude offset, and/or DC offset based upon these various statistical relationships such that their respective digital output samples accurately represent their respective analog inputs.

Abstract: A photonic assembly is described. The assembly comprises a substrate. An optical modulator (100) in or on the substrate has an output port coupled to an output waveguide (106) mounted in or on the substrate. A spiller waveguide (107, 108) is mounted in or on the substrate. The spiller waveguide (107, 108) has an input end (109, 110) physically separated from but proximate to the output waveguide (106) so as to collect light spilt from the output port or output waveguide (106). The modulator (106) may be a MZI modulator.

Abstract: A three-arm-Mach-Zehnder interferometer for splitting/combining first and second wavelength bands is provided, wherein the optical device includes first and second optical splitting/combining elements; a differential optical delay device comprising first, second and third optical paths; the first, second and third optical paths of the differential optical delay device are configured to introduce, at a wavelength ?z within the first optical band, a phase delay of 2?m.

Abstract: Systems and methods for demodulating a plurality of contiguous channels contained within a bandlimited portion of a radio-frequency (RF) input signal are provided. In an embodiment, the bandlimited portion of the RF input signal is down-converted to baseband. After down-conversion, the bandlimited portion overlaps at baseband with a mirror image of the bandlimited portion. The plurality of contiguous channels within the down-converted signal similarly overlap at baseband and subsequently occupy a bandwidth substantially equal to half that required before down-converting. Image rejection is performed in the digital domain to recover each of the plurality of overlapping channels.