General Photonics Corporation

University of Southern California

Lianshan Yan

X Steve Yao

Xiaojun James Chen

Xiaotian Steve Yao

Qian Yu

Alan Eli Willner

Yongqiang Shi

Sanggeon Lee

Zhongqi Pan

Lynn Lin

Devices, systems and techniques for optical communication are provided based on polarization division multiplexing (PDM) to use an optical monitor channel at a distinct optical monitor wavelength to monitor optical polarization fluctuation and polarization mode dispersion during the transmission from the transmitter to the receiver to facilitate the effective demultiplexing of the two orthogonal signal channels at the receiver through automatic feedback control on a dynamic polarization controller and a polarization beam splitter.

Optical polarization division multiplexing in optical communication

Systems, apparatus and methods for characterizing linear retarders using a waveplate analyzer constructed by polarization rotators. In one implementation of such an analyzer, both the retardation of the waveplate sample and the orientation of optical axis of the waveplate sample can be simultaneously measured.

Waveplate analyzer based on multiple tunable optical polarization rotators

Apparatus and methods for scrambling optical modes in multimode fibers to achieve uniform light distribution in guided multi-mode light for various applications.

Mode scrambling apparatus for multimode fiber

Devices and their operations to use multiple adjustable differential group delay (DGD) elements in various applications including tunable PMD emulators and compensators for producing different PMD profiles with an adjustable average DGD value.

Importance sampling techniques based on adjustable differential group delay (DGD) elements

Differential group delay (DGD) devices and techniques based on folded optical paths. An in-line polarization monitor can be provided as a feedback for worst-case alignment without using an in-line polarizer. Polarization maintaining retro reflectors can minimize the introduced higher-order polarization effects caused by reflections between folding mirrors or prisms in conventional schemes.

Optical differential group delay module with folded optical path

Techniques and devices that use polarization rotation and optical interferometry to provide optical spectrum analysis of an optical signal.

Optical spectrum analysis using optical interferometry

Devices and techniques for generating and analyzing states of polarization in light using multiple adjustable polarization rotators in various applications.

Polarization measurement and self-calibration based on multiple tunable optical polarization rotators

Tunable PMD emulators and compensators for producing different PMD profiles with an adjustable average DGD value.

Tunable PMD emulators and compensators

A multi-wavelength optical signal copropagates through a fiber-optic communication link with a continuous-wave ancillary wavelength having an unknown state of polarization (SOP), which is scrambled periodically in time. The instantaneous value of polarization dependent loss (PDL) in the ancillary wavelength is monitored in real time, and is used as an error signal to adjust at least one polarization controller. Polarization scrambling is performed by periodically changing the SOP with time, such that the polarization-scrambled optical signal covers approximately an entire Poincar&#xe9; sphere surface, preferably uniformly, during each time period. At an optical node between fibers, an adjustable PDL compensator contains two ordered pairs each consisting of one polarization controller and one optical element introducing fixed PDL.

Monitoring and in-line compensation of polarization dependent loss for lightwave systems

Techniques and systems for dynamically controlling polarization of an optical signal by using various feedback controls, and by combining both feed-forward and feedback controls. Various dynamic control algorithms for such systems and other optical systems have been disclosed.

Methods and systems for dynamic control of polarization of an optical signal

Techniques for monitoring frequency-dependent parameter and optical property such as optical dispersion in a modulated optical signal with sidebands based on optical vestigial sideband filtering. Monitoring implementations for both chromatic dispersion and polarization-mode dispersion are described as examples.

Monitoring optical dispersion based on vestigial side band optical filtering

An optical device including a beam splitter, polarization controller, and beam combiner is described. In some embodiments, the beam splitter and beam combiner are provided in a single element. An incoming light beam is split into two beams with different polarization components. The polarization of one or both of the beams is rotated using one or two polarization controllers such as fiber squeezers. The beams are then combined, so that a portion of each of the beams is provided to an output. The polarization dependent loss of the device can then be controlled by controlling the polarization rotation. In some embodiments, the rotation is dynamically controlled.

Variable polarization-dependent-loss source

Techniques and devices for controlling or compensating for both the first-order and high-order PMD effects in an optical signal by processing the signal in a fixed DGD stage and a variable DGD stage in sequence.

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Monterey Park, CA, United States of America

Lianshan Yan