Juniper Networks, Inc.

Yang Yue

Qiang Wang

Zhen Qu

Bo Zhang

Xuan He

Xiao Han

Jon J Anderson

Domenico Di Mola

Steven B Alleston

Ryan Holmes

Jeffery J Maki

Chul Soo Park

Murat Arabaci

Robert C Lofland

Jason T O'Neil

A sourceless co-packaged optical-electrical chip can include a plurality of different optical transceivers, each of which can transmit to an external destination or internal components. Each of the transceivers can be configured for a different modulation format, such as different pulse amplitude, phase shift key, and quadrature amplitude modulation formats. Different light sources provide light for processing by the transceivers, where the light source and transceivers can be configured for different applications (e.g., different distances) and data rates. An optical coupler can combine the light for the different transceivers for input into the sourceless co-packaged optical-electrical chip via a polarization maintaining media (e.g., polarization maintaining few mode fiber and polarization maintaining single mode fiber), where another coupler operates in splitting mode to separate the different channels of light for the different transceivers according to different co-packaged configurations.

External laser enabled co-packaged optics architectures

An optical transmitter can generate probabilistically shaped quadrature amplitude modulation (PS-QAM) signaling for transmission over a fiber to a destination without optical amplification. The single fiber can transmit the PS-QAM signaling using dense wavelength division multiplexing having a relatively large number of channels that are closely spaced. A coherent receiver can receive the PS-QAM signaling for decoding without implementing chromatic dispersion compensation.

Probabilistically shaped unamplified optical signaling

A method includes applying, to a modulated digital signal, a forward error correction (FEC) including a low-density parity-check (LDPC) to produce a coded digital signal. Nyquist shaping is applied to the coded digital signal to generate a filtered digital signal. A representation of the filtered digital signal is transmitted in an optical communication channel via a dense wavelength division multiplexing (DWDM) scheme.

Methods and apparatus for optical communications via pulse amplitude modulation (PAM) in dense wavelength-division multiplexing (DWDM) systems

A method includes modulating a digital signal via pulse amplitude modulation (PAM) and applying Nyquist shaping to the digital signal to generate a filtered digital signal. The method also includes converting the filtered digital signal into an analog signal and transmitting the analog signal in an optical communication channel via a dense wavelength division multiplexing (DWDM) scheme.

In some embodiments, an apparatus includes a memory and a processor operatively coupled to the memory. The processor is configured to send a stimulus signal at a frequency that corresponds to a first frequency value to a tributary channel of a coherent optical transponder. The processor is configured to adjust an amplitude of the stimulus signal and receive a first plurality of output optical power values. The processor is configured to adjust the frequency of the stimulus signal and receive a second plurality of output optical power values. The processor is configured to determine a bandwidth limitation and a modulation nonlinearity, and then send a first signal to a first filter to reduce the bandwidth limitation and a second signal to a second filter to reduce the modulation nonlinearity.

Methods and apparatus for detecting and compensating bandwidth limitation and modulation nonlinearity of a coherent optical transponder

In some embodiments, an apparatus includes a memory and a processor operatively coupled to the memory. The processor is configured to be operatively coupled to a first optical transponder and a second optical transponder. The processor is configured to receive, from the second optical transponder, a signal representing a skew value of an optical signal and a signal representing a bit-error-rate (BER) value of the optical signal. The skew value is associated with a skew between an in-phase component of the optical signal and a quadrature component of the optical signal. The processor is configured to determine, based on at least one of the skew value or the BER value, if a performance degradation of the first optical transponder satisfies a threshold. The processor is configured to send a control signal to the first optical transponder to adjust a pulse shaping or a data baud rate of the first optical transponder.

Methods and apparatus for improving the skew tolerance of a coherent optical transponder in an optical communication system

An apparatus includes a finite impulse response (FIR) filter to receive a digital signal and a transmitter, operatively coupled to the FIR filter, to transmit an analog signal, converted from the digital signal, to a communication channel. The FIR filer is configured to change at least one operating parameter based on a bandwidth of the analog signal after transmission in the communication channel. The bandwidth of the analog signal is estimated, using an estimator, based at least in part on raw sampling data generated by an analog-to-digital converter (ADC) operatively coupled to the transmitter.

Methods and apparatus for adaptive compensation of signal bandwidth narrowing through finite impulse response filters

In some embodiments, an apparatus includes a quadrature amplitude modulation (QAM) optical modulator which includes a first phase modulator (PM), a second PM, a tunable optical coupler (TOC), and an optical combiner (OC). The TOC is configured to split a light wave at an adjustable power splitting ratio to produce a first split light wave and a second split light wave. The first PM is configured to modulate the first split light wave in response to a first multi-level electrical signal to produce a first modulated light wave. The second PM is configured to modulate the second split light wave in response to a second multi-level electrical signal to produce a second modulated light wave. The OC is then configured to combine the first modulated light wave and the second modulated light wave to generate a QAM optical signal.

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Milpitas, CA, United States of America

Yang Yue