PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

A quiet phase: NIST optical tools produce ultra-low-noise microwave signals

A quiet phase: NIST optical tools produce ultra-low-noise microwave signals
2011-06-28
(Press-News.org) By combining advanced laser technologies in a new way, physicists at the National Institute of Standards and Technology (NIST) have generated microwave signals that are more pure and stable than those from conventional electronic sources. The apparatus could improve signal stability and resolution in radar, communications and navigation systems, and certain types of atomic clocks.

Described in Nature Photonics,* NIST's low-noise apparatus is a new application of optical frequency combs, tools based on ultrafast lasers for precisely measuring optical frequencies, or colors, of light. Frequency combs are best known as the "gears" for experimental next-generation atomic clocks, where they convert optical signals to lower microwave frequencies, which can be counted electronically.

The new low-noise system is so good that NIST scientists actually had to make two copies of the apparatus just to have a separate tool precise enough to measure the system's performance. Each system is based on a continuous-wave laser with its frequency locked to the extremely stable length of an optical cavity with a high "quality factor," assuring a steady and persistent signal. This laser, which emitted yellow light in the demonstration but could be another color, is connected to a frequency comb that transfers the high level of stability to microwaves. The transfer process greatly reduces—to one-thousandth of the previous level—random fluctuations in the peaks and valleys, or phase, of the electromagnetic waves over time scales of a second or less. This results in a stronger, purer signal at the exact desired frequency.

The base microwave signal is 1 gigahertz (GHz, or 1 billion cycles per second), which is the repetition rate of the ultrafast laser pulses that generate the frequency comb. The signal can also be a harmonic, or multiple, of that frequency. The laser illuminates a photodiode that produces a signal at 1 GHz or any multiple up to about 15 GHz. For example, many common radar systems use signals near 10 GHz.

NIST's low-noise oscillator might be useful in radar systems for detecting faint or slow-moving objects. The system might also be used to make atomic clocks operating at microwave frequencies, such as the current international standard cesium atom clocks, , more stable. Other applications could include high-resolution analog-to-digital conversion of very fast signals, such as for communications or navigation, and radio astronomy that couples signals from space with arrival times at multiple antennas.



INFORMATION:

* T.M. Fortier, M.S. Kirchner, F. Quinlan, J. Taylor, J.C. Bergquist, T. Rosenband, N. Lemke, A. Ludlow, Y. Jiang, C.W. Oates and S.A. Diddams. Generation of ultrastable microwaves via optical frequency division. Nature Photonics. Published online June 26, 2011.

[Attachments] See images for this press release:
A quiet phase: NIST optical tools produce ultra-low-noise microwave signals

ELSE PRESS RELEASES FROM THIS DATE:

LateRooms.com - Judas Priest to Headline Prague Show

2011-06-28
Grammy award-winning heavy metal band Judas Priest will play in Prague later this month. The veteran hard rockers are set to take the stage at the Prague O2 Arena on June 28th as part of a summer European tour taking in cities such as Belgrade, Bucharest, Istanbul and Sofia. Formed in 1969, the band have sold more than 50 million records to date and have been cited as a major influence by many modern alternative musicians. Their twin-lead guitar style, leather-clad appearance and frontman Rob Halford's operatic singing style make them an unforgettable live proposition. Bassist ...

LateRooms.com - The Strokes Prepare to Rock in Milan

2011-06-28
Milan's Fieramilano is preparing to welcome The Strokes for what will be the group's only Italian date on their current tour. Performing on July 12th in the Fiera Rho-Pero area of the venue, the band's gig is part of Flippaut Alternative Reload 2011. The Strokes burst on to the alternative music scene with debut album Is This It in 2001, leaving critics and fans alike spellbound with their infectious and raw, guitar-led sound. Fronted by Julian Casablancas on vocals, the group went on to release another three LPs, including Angles, which was unveiled earlier this ...

Different subtypes of triple-negative breast cancer respond to different therapies

2011-06-28
Vanderbilt-Ingram Cancer Center researchers have identified six subtypes of an aggressive and difficult-to-treat form of breast cancer, called "triple-negative breast cancer (TNBC)." In the July issue of the Journal of Clinical Investigation, Cancer Center Director Jennifer Pietenpol, Ph.D., and colleagues describe the molecular features of these six distinct subtypes and identify chemotherapies to which the different subtypes respond in cultured cells and animal tumor models. Knowing the specific subtype could help physicians determine which therapies would work best ...

Active self-defense strategy best deterrent against cyber-attacks

Active self-defense strategy best deterrent against cyber-attacks
2011-06-28
CHAMPAIGN, Ill. — With the threats of cybercrime, cyberterrorism and cyberwarfare looming over our hyper-connected world, the best defense for the U.S. might be a good offense, says new research by a University of Illinois expert in technology and legal issues. Law professor Jay P. Kesan warns that an active self-defense regime, which he terms "mitigative counterstriking," is a necessity in cyberspace, especially to protect critical infrastructure such as banking, utilities and emergency services. "The threats from cyber-attacks are real, and the harm of a potential ...

Luis Miguel Del Amargue, International Bachata Star, To Perform At The 3rd San Francisco Bachata Festival

2011-06-28
Along with upcoming music star, Alex Wayne as the opening act, Luis Miguel Del Amargue, will not only perform his hit songs, but will be signing autographs promoting his music albums. San Francisco Bachata Festival is known for featuring top notch bachata musicians, and is very proud to host the famous Luis Miguel Del Amargue this year. "He is as popular as Aventura in Europe! I've been listening and dancing to the music of Mr. Amargue for many years. This is why I'm very excited that he will be performing at the festival's peak night, which is on Saturday, ...

Researchers find a keystone nutrient recycler in streams

2011-06-28
Researchers from the University of Georgia Odum School of Ecology have found that certain neotropical stream ecosystems rely almost entirely on a single fish species known as the banded tetra for the critical nutrient phosphorus. In a paper recently published in the journal Ecology, the researchers, led by Gaston E. "Chip" Small, explain why this particular species plays such a crucial role—and why these stream systems are vulnerable as a result. "I initially set out to understand how different physiological factors—diet, fish elemental composition, stream chemistry—interacted ...

July 2011 in GSA Today: Clinker geochronology

2011-06-28
Boulder, Colorado, USA - July GSA Today science article authors Peter W. Reiners of the University of Arizona and colleagues have developed and successfully carried out a novel, extraordinary technique for learning how efficiently river channels cut and increase local topographic relief: They have used the exposure of "clinker" deposits in combination with highly refined dating techniques. Clinkers are baked coals; baking naturally occurs in shallow depths (tens of meters) and when the clinkers are exhumed during erosion and the development of topographic relief, they are ...

Tiny ring laser accurately detects and counts nanoparticles

Tiny ring laser accurately detects and counts nanoparticles
2011-06-28
A tiny doughnut-shaped laser is the latest marvel of silicon microminiaturization, but instead of manipulating bits it detects very small particles. Small particles play a big — and largely unnoticed — role in our everyday lives. Virus particles make us sick, salt particles trigger cloud formation, and soot particles sift deep into our lungs and make it harder to breathe. The sensor belongs to a category called whispering gallery resonators, which work like the famous whispering gallery in St. Paul's Cathedral in London, where someone on the one side of the dome can hear ...

New Research from Ventana Research Identifies Importance of Analytics for Small and Midsized Businesses

2011-06-28
To maintain and improve their market competitiveness, small and midsized businesses are turning to focused analytics that help them manage today's vastly greater information flows, operate more efficiently and make better decisions, new benchmark research from Ventana Research finds. For these businesses the most important categories of metrics are financial (identified by 64% of participants), cost (62%) and operational (53%). However, the research indicates that despite viewing them as valuable and important, small and midsize businesses are maturing only slowly in ...

Baseball cheaters can't hide from the laws of physics

2011-06-28
PULLMAN, Wash.—Some baseball superstitions are accepted as cold, hard truth. But in the world of physics, the most accepted verities are subject to experimentation. A corked bat hits the ball further? Not in Lloyd Smith's lab. Baseballs today are livelier than in the past? See above. Storing balls in a humidor can curb home run production? We'll grant you that one, but only because Smith has fired the balls through a cannon and measured their bounciness as they hit a bat. Smith, an associate professor of in Washington State University's School of Mechanical and Materials ...

LAST 30 PRESS RELEASES:

Exercise as an anti-ageing intervention to avoid detrimental impact of mental fatigue

UMass Amherst Nursing Professor Emerita honored as ‘Living Legend’

New guidelines aim to improve cystic fibrosis screening

Picky eaters by day, buffet by night: Butterfly, moth diets sync to plant aromas

Pennington Biomedical’s Dr. Leanne Redman honored with the E. V. McCollum Award from the American Society for Nutrition

CCNY physicists uncover electronic interactions mediated via spin waves

Researchers’ 3D-printing formula may transform future of foam

Nurture more important than nature for robotic hand

Drug-delivering aptamers target leukemia stem cells for one-two knockout punch

New study finds that over 95% of sponsored influencer posts on Twitter were not disclosed

New sea grant report helps great lakes fish farmers navigate aquaculture regulations

Strain “trick” improves perovskite solar cells’ efficiency

How GPS helps older drivers stay on the roads

Estrogen and progesterone stimulate the body to make opioids

Dancing with the cells – how acoustically levitating a diamond led to a breakthrough in biotech automation

Machine learning helps construct an evolutionary timeline of bacteria

Cellular regulator of mRNA vaccine revealed... offering new therapeutic options

Animal behavioral diversity at risk in the face of declining biodiversity

Finding their way: GPS ignites independence in older adult drivers

Antibiotic resistance among key bacterial species plateaus over time

‘Some insects are declining but what’s happening to the other 99%?’

Powerful new software platform could reshape biomedical research by making data analysis more accessible

Revealing capillaries and cells in living organs with ultrasound

American College of Physicians awards $260,000 in grants to address equity challenges in obesity care

Researchers from MARE ULisboa discover that the European catfish, an invasive species in Portugal, has a prolonged breeding season, enhancing its invasive potential

Rakesh K. Jain, PhD, FAACR, honored with the 2025 AACR Award for Lifetime Achievement in Cancer Research

Solar cells made of moon dust could power future space exploration

Deporting immigrants may further shrink the health care workforce

Border region emergency medical services in migrant emergency care

Resident physician intentions regarding unionization

[Press-News.org] A quiet phase: NIST optical tools produce ultra-low-noise microwave signals