University of Southern California

Guodong Xie

Alan Eli Willner

Yongxiong Ren

Long Li

Cong Liu

Asher J Willner

Yinwen Cao

Hao Huang

Zhe Wang

Zhe Zhao

A system for structuring a directed energy beam includes one or more coherent light sources that emit one or more initial light beams, one or more spatial light modulators that modulate the one or more initial light beams, and a beam combiner that coherently adds orbital angular momentum beams to create a reconfigurable spatial region of localized power that forms the directed energy beam. Each spatial light modulator is loaded with a pattern that receives an incident light beam and outputs an orbital angular momentum beam. The pattern encodes one or more orthogonal orbital angular momentum functions. Characteristically, each orbital angular momentum having an associated complex weight with which each orbital angular momentum beam is weighted in forming the coherent addition.

Spatial light structuring using a combination of multiple orthogonal orbital angular momentum beams with complex coefficients

Methods, systems, and devices for data encoding and channel hopping. The system includes a signal source for providing a signal. The system includes an optical switch having an input port and multiple output paths. The optical switch is configured to receive, at the input port, the signal. The optical switch is configured to route the signal to an output path of the multiple output paths. The system includes a mode converter that is connected to the optical switch and configured to select an orbital angular momentum (OAM) mode. The mode converter is configured to encode or channel hop the signal using the OAM mode and combine the signal from each output path. The system includes a transmitter configured to propagate the signal.

Data encoding and channel hopping using orbital angular momentum modes

A system includes a transmitter with multiple transmit devices each having an OAM multiplexer that converts multiple input signals into an OAM beam. Each transmit device outputs a coaxial group of orthogonal OAM beams. The system also includes a receiver that has multiple receive devices each having an OAM demultiplexer that receives the group of OAM beams from a corresponding transmit device. The OAM demultiplexer also converts the coaxial group of mutually orthogonal OAM beams into a plurality of received signals corresponding to input signals represented by the OAM beams. The receiver also includes a MIMO processor that has an equalizer that determines a transfer function corresponding to crosstalk of each of the plurality of received signals. The MIMO processor also reduces the crosstalk of each of the plurality of received signals based on the transfer function and updates the transfer function.

Systems and techniques for communication using combined orbital angular momentum and multiple-input-multiple-output processing

An adaptive optics compensation approach for an OAM multiplexed FSO communication system is described, in which a Gaussian beam is used to probe the turbulence-induced wavefront distortions and derive the correction pattern for compensating the OAM beams. Using this approach, we demonstrate simultaneous compensation of multiple OAM beams each carrying a 100-Gbit/s data channel through emulated atmospheric turbulence. The results indicate that the turbulence-induced crosstalk and power penalty could be efficiently mitigated by &#x2dc;12.5 dB and &#x2dc;11 dB respectively.

Growing community of inventors

Los Angeles, CA, United States of America

Guodong Xie