From American Institute of Physics-AIP (US) via phys.org : “Boosting fiber optics communications with advanced quantum-enhanced receiver”

From American Institute of Physics-AIP (US)

via

phys.org

April 20, 2021

1
Illustration showing how single-photon detection is used for feedback. Once correct parameters for the reference beam are established, the input state is extinguished. Credit: Ivan Burenkov.

Fiber optic technology is the holy grail of high-speed, long-distance telecommunications. Still, with the continuing exponential growth of internet traffic, researchers are warning of a capacity crunch.

In AVS Quantum Science, researchers from the National Institute of Standards and Technology (US) and the University of Maryland (US) show how quantum-enhanced receivers could play a critical role in addressing this challenge.

The scientists developed a method to enhance receivers based on quantum physics properties to dramatically increase network performance while significantly reducing the error bit rate (EBR) and energy consumption.

Fiber optic technology relies on receivers to detect optical signals and convert them into electrical signals. The conventional detection process, largely as a result of random light fluctuations, produces ‘shot noise,’ which decreases detection ability and increases EBR.

To accommodate this problem, signals must continually be amplified as pulsating light becomes weaker along the optic cable, but there is a limit to maintaining adequate amplification when signals become barely perceptible.

Quantum-enhanced receivers that process up to two bits of classical information and can overcome the shot noise have been demonstrated to improve detection accuracy in laboratory environments. In these and other quantum receivers, a separate reference beam with a single-photon detection feedback is used so the reference pulse eventually cancels out the input signal to eliminate the shot noise.

The researchers’ enhanced receiver, however, can decode as many as four bits per pulse, because it does a better job in distinguishing among different input states.

To accomplish more efficient detection, they developed a modulation method and implemented a feedback algorithm that takes advantage of the exact times of single photon detection. Still, no single measurement is perfect, but the new holistically designed communication system yields increasingly more accurate results on average.

“We studied the theory of communications and the experimental techniques of quantum receivers to come up with a practical telecommunication protocol that takes maximal advantage of the quantum measurement,” author Sergey Polyakov said. “With our protocol, because we want the input signal to contain as few photons as possible, we maximize the chance that the reference pulse updates to the right state after the very first photon detection, so at the end of the measurement, the EBR is minimized.”

See the full article here.

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The American Institute of Physics (AIP) promotes science and the profession of physics, publishes physics journals, and produces publications for scientific and engineering societies. The AIP is made up of various member societies. Its corporate headquarters are at the American Center for Physics in College Park, Maryland, but the institute also has offices in Melville, New York, and Beijing.

The focus of the AIP appears to be organized around a set of core activities. The first delineated activity is to support member societies regarding essential society functions. This is accomplished by annually convening the various society officers to discuss common areas of concern. A range of topics is discussed which includes scientific publishing, public policy issues, membership-base issues, philanthropic giving, science education, science careers for a diverse population, and a forum for sharing ideas.

Another core activity is publishing the science of physics in research journals, magazines, and conference proceedings. Member societies continue nevertheless to publish their own journals.

Other core activities are tracking employment and education trends with six decades of coverage, being a liaison between research science and industry, historical collections and physics outreach programs, and supporting science education initiatives and supporting undergraduate physics. One other core activity is as an advocate for science policy to the U.S. Congress and the general public.

Member societies:
Acoustical Society of America
American Association of Physicists in Medicine
American Association of Physics Teachers
American Astronomical Society
American Crystallographic Association
American Meteorological Society
American Physical Society
American Vacuum Society

Affiliated societies

American Association for the Advancement of Science, Section on Physics
American Chemical Society, Division of Physical Chemistry
American Institute of Aeronautics and Astronautics
American Nuclear Society
American Society of Civil Engineers
ASM International
Astronomical Society of the Pacific
Biomedical Engineering Society
Council on Undergraduate Research, Physics & Astronomy Division
Electrochemical Society
Geological Society of America
IEEE Nuclear and Plasma Sciences Society
International Association of Mathematical Physics
International Union of Crystallography
International Centre for Diffraction Data
Health Physics Society