. 24/7 Space News .
PHYSICS NEWS
Precision mirrors poised to improve sensitivity of gravitational wave detectors
by Staff Writers
Washington DC (SPX) Mar 19, 2020

The illustration shows the cross-section of a thermal bimorph mirror and its constituents. Controlling the temperature of the mirror changes the curvature of the reflected wavefront. Overlaid on the cross-section is the simulated radial stress, showing a concentration of stress at the boundary of the two layers, where the adhesive holds the structure together.

Researchers have developed a new type of deformable mirror that could increase the sensitivity of ground-based gravitational wave detectors such as the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO). Advanced LIGO measures faint ripples in space time called gravitational waves, which are caused by distant events such as collisions between black holes or neutron stars.

"In addition to improving today's gravitational wave detectors, these new mirrors will also be useful for increasing sensitivity in next generation detectors and allow detection of new sources of gravitational waves," said research team leader Huy Tuong Cao from the University of Adelaide node of the Australian Center of Excellence for Gravitational Waves Discovery (OzGrav).

Deformable mirrors, which are used to shape and control laser light, have a surface made of tiny mirrors that can each be moved, or actuated, to change the overall shape of the mirror. As detailed in The Optical Society's (OSA) journal Applied Optics, Cao and colleagues have, for the first time, made a deformable mirror based on the bimetallic effect in which a temperature change is used to achieve mechanical displacement.

"Our new mirror provides a large actuation range with great precision," said Cao. "The simplicity of the design means it can turn commercially available optics into a deformable mirror without any complicated or expensive equipment. This makes it useful for any system where precise control of beam shape is crucial."

The new technology was conceived by Cao and Aidan Brooks of LIGO as part of a visitor program between the University of Adelaide and LIGO Laboratory, funded by the Australian Research Council and National Science Foundation.

Building a better mirror
Ground-based gravitational wave detectors use laser light traveling back and forth down an interferometer's two arms to monitor the distance between mirrors at each arm's end. Gravitational waves cause a slight but detectable variation in the distance between the mirrors.

Detecting this tiny change requires extremely precise laser beam steering and shaping, which is accomplished with a deformable mirror.

"We are reaching a point where the precision needed to improve the sensitivity of gravitational wave detectors is beyond what can be accomplished with the fabrication techniques used to make deformable mirrors," said Cao.

Most deformable mirrors use thin mirrors to induce large amount of actuation, but these thin mirrors can produce undesirable scattering because they are hard to polish. The researchers designed a new type of deformable mirror using the bimetallic effect by attaching a piece of metal to a glass mirror. When the two are heated together the metal expands more than the glass, causing the mirror to bend.

The new design not only creates a large amount of precise actuation but is also compact and requires minimum modifications to existing systems. Both the fused silica mirrors and aluminum plates used to create the deformable mirror are commercially available. To attach the two layers, the researchers carefully selected a bonding adhesive that would maximize actuation.

"Importantly, the new design has fewer optical surfaces for the laser beam to travel through, said Cao. "This reduces light loss caused by scattering or absorption of coatings."

Precision characterization
Creating a highly precise mirror requires precision characterization techniques. The researchers developed and built a highly sensitive Hartmann wave front sensor to measure how the mirror's deformations changed the shape of laser light.

"This sensor was crucial to our experiment and is also used in gravitational detectors to measure minute changes in the core optics of the interferometer," said Cao. "We used it to characterize the performance of our mirrors and found that the mirrors were highly stable and have a very linear response to changes in temperature."

The tests also showed that the adhesive is the main limiting factor for the mirrors' actuation range. The researchers are currently working to overcome the limitation caused by the adhesive and will perform more tests to verify compatibility before incorporating the mirrors into Advanced LIGO.

Research Report: "A high dynamic-range thermally-actuated bimorph mirror for gravitational wave detectors"


Related Links
The Optical Society
The Physics of Time and Space


Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Monthly Supporter
$5+ Billed Monthly


paypal only
SpaceDaily Contributor
$5 Billed Once


credit card or paypal


PHYSICS NEWS
Continued Gravitational-Wave Discoveries from Public Data
Hannover, Germany (SPX) Mar 16, 2020
Researchers from the Max Planck Institute for Gravitational Physics (Albert Einstein Institute, AEI) in Hannover together with international colleagues have published their second Open Gravitational-wave Catalog (2-OGC). They used improved search methods to dig deeper into publicly available data from LIGO's and Virgo's first and second observation runs. Apart from confirming the 10 known binary black hole mergers and one binary neutron star merger, they also identify four promising black hole mer ... read more

Comment using your Disqus, Facebook, Google or Twitter login.



Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

PHYSICS NEWS
Astronauts grounded in Russia's Star City over virus

Science takes time, even in a lab moving 17,500 miles per hour

Beyond human toll, coronavirus could shake up global politics

Insects, seaweed and lab-grown meat could be the foods of the future

PHYSICS NEWS
Student Launch adjusts competition structure to remove need for travel

SpaceX aborts Sunday launch from Florida at last moment

NASA's mobile moon rocket tower 44% over budget, IG says

Spacex Falcon 9 launches sixth batch of Starlink satellites

PHYSICS NEWS
Europe-Russia delay mission to find life on Mars

ExoMars to take off for the Red Planet in 2022

Waves in thin Martian air with wide effects

Organic molecules discovered by Curiosity Rover consistent with early life on Mars

PHYSICS NEWS
China's Long March-7A carrier rocket fails in maiden flight

China's Yuanwang-5 sails to Pacific Ocean for space monitoring mission

Construction of China's space station begins with start of LM-5B launch campaign

China Prepares to Launch Unknown Satellite Aboard Long March 7A Rocket

PHYSICS NEWS
Soyuz to launch another batch of OneWeb constellation satellites

Coronavirus and ESA's duty of care

Hughes and OneWeb form Global Distribution Partnership for LEO satellite service

Making aerospace workforce training a national mandate for the future

PHYSICS NEWS
European Gateway experiment will monitor radiation in deep space

RUAG Space to supply payload adapters and separation systems for the Soyuz launchers

L3Harris Technologies introduces new reflector antenna tailored for smallsat missions

Raytheon completes first tests of radar for anti-hypersonic sensor

PHYSICS NEWS
Scientists have discovered the origins of the building blocks of life

Salmon parasite is world's first non-oxygen breathing animal

Observed: An exoplanet where it rains iron

ESO telescope observes exoplanet where it rains iron

PHYSICS NEWS
Jupiter's Great Red Spot shrinking in size, not thickness

Researchers find new minor planets beyond Neptune

Ultraviolet instrument delivered for ESA's Jupiter mission

One Step Closer to the Edge of the Solar System









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.