Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NIST quantum probe enhances electric field measurements

08.10.2014

Researchers at the National Institute of Standards and Technology (NIST) and the University of Michigan have demonstrated a technique based on the quantum properties of atoms that directly links measurements of electric field strength to the International System of Units (SI).*

The new method could improve the sensitivity, precision and ease of tests and calibrations of antennas, sensors, and biomedical and nano-electronic systems and facilitate the design of novel devices.


This is an animation of NIST's new method for measuring electric field strength based on the quantum properties of atoms. The technique works for abroad range of frequencies, 1-500 gigahertz, and directly links measurements to the International System of Units. The method could improve the sensitivity, precision and ease of tests and calibrations of antennas, sensors, and other systems.

Credit: Sean Kelley/NIST

Conventional electric field probes have limited frequency range and sensitivity, often disturb the field being measured, and require laboratory calibrations that are inherently imprecise (because the reference field depends on the geometry of the source). Furthermore, linking these measurements to SI units, the highest level of calibration, is a complex process.

NIST's new electric-field probe spans enormous ranges. It can measure the strength of fields from 1 to 500 gigahertz, including the radio, microwave, millimeter-wave and sub-terahertz bands. It can measure fields up to 100 times weaker than conventional methods can (as weak as 0.8millivolts per meter, the SI unit of measure). Researchers used the new method to measure field strengths for a wide range of frequencies, and the results agreed with both numerical simulations and calculations.

Importantly, the new method can calibrate itself, as well as other instruments, because it is based on predictable quantum properties: vibrations in atoms as they switch between energy levels. This self-calibration feature improves measurement precision and may make traceable calibrations possible in the millimeter and sub-terahertz bands of the spectrum for the first time.

"The exciting aspect of this approach is that an atom is rich in the number of transitions that can be excited," NIST project leader Chris Holloway says. "This results in a broadband measurement probe covering a frequency range of 1 to 500 gigahertz and possibly up to 1 terahertz."

The NIST instrument currently is tabletop sized, but researchers are working on miniaturizing it using photonic structures.

The basic method has already been demonstrated for imaging applications.** Briefly, researchers use a red and a blue laser to prepare atoms contained in a cylinder to high-energy ("Rydberg") states, which have novel properties such as extreme sensitivity and reactivity to electromagnetic fields. An antenna or other source generates an electric field, which, depending on its frequency, affects the spectrum of light absorbed by the atoms. By measuring this effect, researchers can calculate the field strength. Various atoms can be used—NIST uses rubidium or cesium—to measure field strength in different parts of the frequency spectrum.

Among possible applications, the NIST probe may be suitable for measuring and optimizing compatibility in densely packaged electronics that include radar and wireless communications and control links, and for integration into endoscopic probes with medical applications such as investigating implants in the body. The technique might also be included in a future "NIST on a chip" offering multiple measurement methods and standards in a portable form.

Importantly, the technique also enables, for the first time, calibrated measurements of frequencies above 100 GHZ, in the millimeter wave and sub-terahertz bands.*** This capability will be crucial for the development of advanced communications systems and climate change research, among other applications.

###

Five co-authors of the new paper are with the University of Michigan, which provided the blue laser and aided in the experiments. The project is funded in part by the Defense Advanced Research Projects Agency.

* C.L. Holloway, J.A. Gordon, S. Jefferts, A. Schwarzkopf, D. A. Anderson, S.A. Miller, N. Thaicharoen and G. Raithelet. Broadband Rydbergatom-based electric-field probe: From self-calibrated measurements to sub-wavelength imaging. IEEE Trans. on Antennas and Propagation. 99. Accepted for publication. DOI: 10.1109/TAP.2014.2360208.

** See 2014 NIST Tech Beat article, "NIST Technique Could Make Sub-wavelength Images at Radio Frequencies," at http://www.nist.gov/pml/electromagnetics/subwave-061714.cfm.

*** J.A. Gordon, C.L. Holloway, A. Schwarzkopf, D. A. Anderson, S. Miller, N. Thaicharoen and G. Raithel. Millimeter wave detection via Autler-Townes splitting in rubidium Rydberg atoms. Applied Physics Letters, 2014. Vol. 105, Issue 2.DOI:10.1063/1.4890094.

Laura Ost | Eurek Alert!

More articles from Physics and Astronomy:

nachricht What happens when we heat the atomic lattice of a magnet all of a sudden?
17.07.2018 | Forschungsverbund Berlin

nachricht Subaru Telescope helps pinpoint origin of ultra-high energy neutrino
16.07.2018 | National Institutes of Natural Sciences

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Microscopic trampoline may help create networks of quantum computers

17.07.2018 | Information Technology

In borophene, boundaries are no barrier

17.07.2018 | Materials Sciences

The role of Sodium for the Enhancement of Solar Cells

17.07.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>