Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New design for 'optical ruler' could revolutionize clocks, telescopes, telecommunications

23.06.2020

Just as a meter stick with hundreds of tick marks can be used to measure distances with great precision, a device known as a laser frequency comb, with its hundreds of evenly spaced, sharply defined frequencies, can be used to measure the colors of light waves with great precision.

Small enough to fit on a chip, miniature versions of these combs -- so named because their set of uniformly spaced frequencies resembles the teeth of a comb -- are making possible a new generation of atomic clocks, a great increase in the number of signals traveling through optical fibers, and the ability to discern tiny frequency shifts in starlight that hint at the presence of unseen planets.


Experimental setup to generate a set of stable frequencies in a cryogenically cooled laser microresonator frequency comb. The ring-shaped microresonator, small enough to fit on a microchip, operates at very low laser power and is made from the semiconductor aluminum gallium arsenide.

Credit: NIST

The newest version of these chip-based "microcombs," created by researchers at the National Institute of Standards and Technology (NIST) and the University of California at Santa Barbara (UCSB), is poised to further advance time and frequency measurements by improving and extending the capabilities of these tiny devices.

At the heart of these frequency microcombs lies an optical microresonator, a ring-shaped device about the width of a human hair in which light from an external laser races around thousands of times until it builds up high intensity.

Microcombs, often made of glass or silicon nitride, typically require an amplifier for the external laser light, which can make the comb complex, cumbersome and costly to produce.

The NIST scientists and their UCSB collaborators have demonstrated that microcombs created from the semiconductor aluminum gallium arsenide have two essential properties that make them especially promising.

The new combs operate at such low power that they do not need an amplifier, and they can be manipulated to produce an extraordinarily steady set of frequencies -- exactly what is needed to use the microchip comb as a sensitive tool for measuring frequencies with extraordinary precision. (The research is part of the NIST on a Chip program.)

The newly developed microcomb technology can help enable engineers and scientists to make precision optical frequency measurements outside the laboratory, said NIST scientist Gregory Moille. In addition, the microcomb can be mass-produced through nanofabrication techniques similar to the ones already used to manufacture microelectronics.

The researchers at UCSB led earlier efforts in examining microresonators composed of aluminum gallium arsenide. The frequency combs made from these microresonators require only one-hundredth the power of devices fabricated from other materials.

However, the scientists had been unable to demonstrate a key property -- that a discrete set of unwavering, or highly stable, frequencies could be generated from a microresonator made of this semiconductor.

The NIST team tackled the problem by placing the microresonator within a customized cryogenic apparatus that allowed the researchers to probe the device at temperatures as low as 4 degrees above absolute zero.

The low-temperature experiment revealed that the interaction between the heat generated by the laser light and the light circulating in the microresonator was the one and only obstacle preventing the device from generating the highly stable frequencies needed for successful operation.

At low temperatures, the team demonstrated that it could reach the so-called soliton regime -- where individual pulses of light that never change their shape, frequency or speed circulate within the microresonator. The researchers describe their work in the June issue of Laser and Photonics Reviews.

With such solitons, all teeth of the frequency comb are in phase with each other, so that they can be used as a ruler to measure the frequencies employed in optical clocks, frequency synthesis, or laser-based distance measurements.

Although some recently developed cryogenic systems are small enough that they could be used with the new microcomb outside the laboratory, the ultimate goal is to operate the device at room temperature. The new findings show that scientists will either have to quench or entirely avoid excess heating to achieve room-temperature operation.

Media Contact

Ben P. Stein
benjamin.stein@nist.gov
301-975-2763

 @NIST

http://www.nist.gov 

Ben P. Stein | EurekAlert!
Further information:
https://www.nist.gov/news-events/news/2020/06/comb-chip-new-design-optical-ruler-could-revolutionize-clocks-telescopes
http://dx.doi.org/10.1002/lpor.202000022

More articles from Physics and Astronomy:

nachricht Excitation of robust materials
07.07.2020 | Christian-Albrechts-Universität zu Kiel

nachricht FAST detects neutral hydrogen emission from extragalactic galaxies for the first time
02.07.2020 | Chinese Academy of Sciences Headquarters

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: Excitation of robust materials

Kiel physics team observed extremely fast electronic changes in real time in a special material class

In physics, they are currently the subject of intensive research; in electronics, they could enable completely new functions. So-called topological materials...

Im Focus: Electrons in the fast lane

Solar cells based on perovskite compounds could soon make electricity generation from sunlight even more efficient and cheaper. The laboratory efficiency of these perovskite solar cells already exceeds that of the well-known silicon solar cells. An international team led by Stefan Weber from the Max Planck Institute for Polymer Research (MPI-P) in Mainz has found microscopic structures in perovskite crystals that can guide the charge transport in the solar cell. Clever alignment of these "electron highways" could make perovskite solar cells even more powerful.

Solar cells convert sunlight into electricity. During this process, the electrons of the material inside the cell absorb the energy of the light....

Im Focus: The lightest electromagnetic shielding material in the world

Empa researchers have succeeded in applying aerogels to microelectronics: Aerogels based on cellulose nanofibers can effectively shield electromagnetic radiation over a wide frequency range – and they are unrivalled in terms of weight.

Electric motors and electronic devices generate electromagnetic fields that sometimes have to be shielded in order not to affect neighboring electronic...

Im Focus: Gentle wall contact – the right scenario for a fusion power plant

Quasi-continuous power exhaust developed as a wall-friendly method on ASDEX Upgrade

A promising operating mode for the plasma of a future power plant has been developed at the ASDEX Upgrade fusion device at Max Planck Institute for Plasma...

Im Focus: ILA Goes Digital – Automation & Production Technology for Adaptable Aircraft Production

Live event – July 1, 2020 - 11:00 to 11:45 (CET)
"Automation in Aerospace Industry @ Fraunhofer IFAM"

The Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM l Stade is presenting its forward-looking R&D portfolio for the first time at...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Contact Tracing Apps against COVID-19: German National Academy Leopoldina hosts international virtual panel discussion

07.07.2020 | Event News

International conference QuApps shows status quo of quantum technology

02.07.2020 | Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

 
Latest News

Quick notes in the genome

07.07.2020 | Life Sciences

Limitations of Super-Resolution Microscopy Overcome

07.07.2020 | Life Sciences

Put into the right light - Reproducible and sustainable coupling reactions

07.07.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>