Juniper Networks, Inc.

Murat Arabaci

Theodore John Schmidt

Christian Malouin

Roberto Marcoccia

Philip A Thomas

Bo Zhang

Steven William Keck

David James Ofelt

Massimiliano Salsi

Marianna Pepe

Qiang Wang

Yang Yue

In some embodiments, an apparatus includes an optical transmitter module that can be electrically coupled to an electrical serializer/deserializer and a controller. The optical transmitter module can include an electrical detector that can receive an in-band signal. The electrical detector can send to the controller a first power error signal and a second power error signal based on the in-band signal. The controller can send a correction control signal to the electrical serializer/deserializer based on the first power error signal and the second power error signal such that the electrical serializer/deserializer sends a pre-emphasized signal to the optical transmitter module based on the correction control signal. In such embodiments, the first power error signal, the second power signal and the correction control signal are out-of-band signals.

Method and apparatus for distortion correction in optical communication links

In some embodiments, an apparatus includes an optical transceiver which includes a rate-adaptive forward error correction (FEC) encoder and a rate-adaptive FEC decoder. The rate-adaptive FEC encoder is configured to adjust a number of a set of known symbols associated with a codeword to achieve rate adaption. A length of the codeword is fixed. The rate-adaptive FEC encoder is configured to generate the codeword based on (1) a set of information symbols including the set of known symbols and a set of data symbols, and (2) a fixed number of a set of parity symbols generated using information symbols. The rate-adaptive FEC decoder is configured to receive a set of reliability values associated with a channel word, and expand the set of reliability values to produce an expanded set of reliability values. The rate-adaptive FEC decoder is further configured to decode the expanded set of reliability values.

Methods and apparatus for flexible overhead forward error correction (FEC) sub-system for optical fiber communication systems

Techniques are described for characterizing a receiver front end of a pluggable optical module. The pluggable optical module receives an optical signal that includes a first portion having a first polarization and a second portion having a second polarization. The first portion and second portion are not coherent with one another and the power of the first portion and second portion is equal.

Front end characterization of coherent receiver

Techniques are described for determining pre-compensation parameters to compensate for signal integrity degradation along a signal path. A processor generates a first digital signal and receives a second digital signal. The second digital signal is generated from an optical-to-electrical conversion of a feedback optical signal that is generated from an electrical-to-optical conversion of an electrical signal by an optical module. The processor determines the pre-compensation parameters based on the first and second digital signals.

Self-calibration of pluggable optical module

In some embodiments, an apparatus includes a coherent optical receiver that can receive during a first time period a set of in-phase signals and a set of quadrature signals having a skew from the set of in-phase signals. The coherent receiver can blindly determine a delay between the set of in-phase signals and the set of quadrature signals based on the set of in-phase signals and the set of quadrature signals. The delay includes an intersymbol portion and an intrasymbol portion. The coherent optical receiver can apply the delay at a second time after the first time period such that a skew after the second time is less than the skew at the first time period.

Method and apparatus for blind time skew compensation for coherent optical receivers

This disclosure describes the Fast Chromatic Dispersion Estimation (FCDE) techniques which corrects for chromatic dispersion in high data rate optical communications systems such as some coherent optical communications systems. FCDE may utilize transform such as fast-Fourier transforms to estimate the chromatic dispersion. From an estimate of the chromatic dispersion, the techniques may determine filter tap coefficients for compensating the chromatic dispersion.

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San Jose, CA, United States of America

Murat Arabaci