Infinera Corporation

Hai Xu

Pierre Mertz

Michael Francis Van Leeuwen

Stephen G Grubb

John Duncan McNicol

Jeffrey Thomas Rahn

Emily F Burmeister

Consistent with the present disclosure, chromatic dispersion is introduced into an optical communication path including multiple segments or spans of dispersion shifted fiber (DSF). The chromatic dispersion generates phase mismatching between optical signals propagating along the optical communication path, i.e., the optical signals are decorrelated, such that mixing products are reduced inmagnitude, and the noise attributable to four wave mixing is correspondingly reduced.

Suppression of non-linear effects in low dispersion optical fibers

Systems and methods are disclosed including a subsea link idler apparatus comprising at least one data laser generating a first laser beam as a data signal, having a first frequency within a first data channel bandwidth slot; a first continuous wave laser generating a second laser beam with a first polarization and a second frequency being within a second data channel bandwidth slot; a second continuous wave laser generating a third laser beam with a second polarization different from the first polarization and a third frequency being offset from the second frequency and being within the second data channel bandwidth slot; a polarization beam combiner positioned in paths of the second and third laser beams combining the second and third laser beams into an idler signal; and a transmitter receiving and transmitting the data signal and idler signal.

Subsea optical communication system dual polarization idler

Consistent with the present disclosure, data, in digital form, is received by a transmit node of an optical communication system, and is then provided to a modulator that, in turn, modulates light, received from an optical source at one of a plurality of periodically and preferably minimally spaced wavelengths. The plurality of periodically spaced wavelengths or carriers are grouped together with minimal carrier spacing, to form a superchannel. The carrier spacing between adjacent carriers is determined by detecting a beat frequency of a combined optical signal that includes the outputs of two adjacent optical sources. The beat frequency corresponds to a frequency difference between the outputs of the adjacent carriers. This frequency difference should correspond to a desired carrier spacing between each of the plurality of carriers. A frequency error between the beat frequency and the desired carrier spacing is then measured by down-converting the beat frequency with respect to a target reference frequency corresponding to the desired carrier frequency spacing. Based on the determined frequency error, the optical sources are controlled to adjust in frequency to minimize or reduce the frequency error to zero. For every pair of adjacent carriers, the corresponding outputs of the optical sources are compared in the above manner to determine a plurality of frequency errors. Each optical source can thus be tuned in order to realize a precise carrier spacing between each of the adjacent carriers.

Apparatus to control carrier spacing in a multi-carrier optical transmitter

A compensator device may include a selection switch to receive a first optical signal and provide first and second groups of channels associated with the first optical signal; a polarization beam splitter to receive the first channels, and provide first and second components; a photodiode that provides an electrical signal indicative of an intensity of the first group of channels; a first modulator to receive the electrical signal and the first components and to modulate the first components to form first modulated channels; a second modulator to receive the electrical signal and the second components to modulate the second components to form second modulated channels; a polarization beam combiner to receive the first and second modulated channels to form combined modulated channels; and a coupler to receive the combined modulated channels and the second group of channels to form a second optical signal.

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North Laurel, MD, United States of America

Hai Xu