. 24/7 Space News .
STELLAR CHEMISTRY
New way to make telescope mirrors could sharpen our view of the universe
by Staff Writers
Boston MA (SPX) Oct 24, 2022

Researchers developed a new way to use femtosecond laser pulses to fabricate the high-precision ultrathin mirrors required for high-performance x-ray telescopes. Femtosecond laser surface ablation is applied to selectively remove stressed film regions on the mirror substrate, correcting the shape of the mirror's reflective surface.

Researchers have developed a new way to use femtosecond laser pulses to fabricate the high-precision ultrathin mirrors required for high-performance x-ray telescopes. The technique could help improve the space-based x-ray telescopes used to capture high-energy cosmic events involved in forming new stars and supermassive black holes.

"Detecting cosmic x-rays is a crucial piece of our exploration of the universe that unveils the high-energy events that permeate our universe but are not observable in other wavebands," said research team leader Heng Zuo, who performed the research at MIT Kavli Institute for Astrophysics and Space Research and is now at the University of New Mexico. "The technologies our group developed will help telescopes obtain sharp images of astronomical x-rays that can answer many intriguing science questions."

X-ray telescopes orbit above the Earth's atmosphere and contain thousands of thin mirrors that must each have a precisely curved shape and be carefully aligned with respect to all the other mirrors. In Optica, Optica Publishing Group's journal for high-impact research, the researchers describe how they used femtosecond laser micromachining to bend these ultrathin mirrors into a precise shape and correct errors that can arise in the fabrication process.

"It is difficult to make ultra-thin mirrors with an exact shape because the fabrication process tends to severely bend the thin material," said Zuo. "Also, telescope mirrors are usually coated to increase reflectivity, and these coatings typically deform the mirrors further. Our techniques can address both challenges."

Precision bending
New ways to fabricate ultra-precise and high-performance x-ray mirrors for telescopes are needed as new mission concepts continue to push the limits of x-ray imaging. For example, NASA's Lynx X-ray Surveyor concept will have the most powerful x-ray optic ever conceived and will require the manufacture of a large number of ultra-high-resolution mirrors.

To meet this need, Zuo's research group combined femtosecond laser micromachining with a previously developed technique called stress-based figure correction. Stress-based figure correction exploits the bendability of thin mirrors by applying a deformable film to the mirror substrate to adjust its stress states and induce controlled bending.

The technique involves selectively removing regions of a stressed film grown onto the back surface of a flat mirror. The researchers selected femtosecond lasers to accomplish this because the pulses produced by these lasers can create extremely precise holes, channels and marks with little collateral damage. Also, the high repetition rates of these lasers allow faster machining speeds and throughput compared to traditional methods. This could help speed up fabrication for the large numbers of ultra-thin mirrors required for next-generation x-ray telescopes.

Mapping stress
To carry out the new approach the researchers first had to determine exactly how laser micromachining changes the mirror's surface curvature and stress states. Then they measured the initial mirror shape and created a map of the stress correction necessary to create the desired shape. They also developed a multi-pass correction scheme that uses a feedback loop to repeatedly reduce errors until an acceptable mirror profile is achieved.

"Our experimental results showed that patterned removal of periodic holes leads to equibiaxial (bowl-shaped) stress states, while fine-pitched oriented removal of periodic troughs generates non-equibiaxial (potato-chip-shaped) stress components," said Zuo. "Combining these two features with proper rotation of the trough orientation we can create a variety of stress states that can, in principle, be used to correct for any type of error in the mirrors."

In this work, the researchers demonstrated the new technique on flat silicon wafers using regular patterns. To correct real x-ray astronomy telescope mirrors, which are curved in two directions, the researchers are developing a more complex optical setup for 3D movement of the substrates.

Research Report:Femtosecond laser micromachining for stress-based figure correction of thin mirrors


Related Links
Massachusetts Institute of Technology
Stellar Chemistry, The Universe And All Within It


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


STELLAR CHEMISTRY
Webb uncovers dense cosmic knot in the early Universe
Paris (ESA) Oct 21, 2022
Astronomers looking into the early Universe have made a surprising discovery using the NASA/ESA/CSA James Webb Space Telescope. Webb's spectroscopic capabilities, combined with its infrared sensitivity, have uncovered a cluster of massive galaxies in the process of formation around an extremely red quasar. The result will expand our understanding of how galaxies in the early Universe coalesced into the cosmic web we see today. The quasar in question, SDSS J165202.64+172852.3, is an "extremely red" ... 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

STELLAR CHEMISTRY
NASA generated $71 billion in economic impact in 2021

NASA to resume spacewalks after investigation into 'close call'

NASA Crew-4 astronauts safely splash down in Atlantic

Eagle-designed space drones target in-orbit construction

STELLAR CHEMISTRY
UCF researcher receives NASA award to develop revolutionary rocket engine technology

AFRL upgrades rocket fabrication capabilities

Gilmour Space partners with Equipmake on advanced motors for rocket program

China completes test of vacuum liquid oxygen-methane rocket engine

STELLAR CHEMISTRY
Meteorite that smashed into Mars shook planet

Trying to Avoid Nodules: Sols 3633-3634

Ancient bacteria might lurk beneath Mars' surface

Driving on the Sidewalk, MARDI-Style: Sols 3630-3632

STELLAR CHEMISTRY
Mengtian space lab to undergo final tests before launch

China's deep space exploration laboratory recruits young talents

Thermal control designs keep astronauts cool on space station

China to invest in major space programs

STELLAR CHEMISTRY
SpaceX announces Starlink Internet service on airplanes

Spacecraft manufacturer Apex emerges from stealth with $7.5M in funding

Designing the trajectory of a microsatellite swarm from the macro-micro perspective

ISRO launches 36 OneWeb satellites

STELLAR CHEMISTRY
NASA inflatable heat shield finds strength in flexibility

D-Orbit announces launch contract with Elecnor Deimos for ALISIO-1

D-Orbit signs launch contract with AAC SpaceQuest

International Space Station maneuvers to avoid debris

STELLAR CHEMISTRY
Discovery could dramatically narrow search for space creatures

Discovery could dramatically narrow search for space creatures

New technique to determine age will open new era of planetary science

Secret behind spectacular blooms in world's driest desert is invisible to human eyes

STELLAR CHEMISTRY
Mars and Jupiter moons meet

NASA studies origins of dwarf planet Haumea

NASA study suggests shallow lakes in Europa's icy crust could erupt

Sharpest Earth-based images of Europa and Ganymede reveal their icy landscape









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.