Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Magnetic mirror could shed new light on gravitational waves and the early universe

14.12.2016

Device modulates polarization across wide range of microwave frequencies to map radiation from shortly after the Big Bang

Researchers have created a new magnetic mirror-based device that could one day help cosmologists discover new details about ripples in space-time known as gravitational waves, particularly those emitted when the universe was extremely young.


Researchers have created a new metamaterial half-wave plate operating at millimeter wavelengths that is less than 1-millimeter thick. When light reflects off the device, the polarization parallel to the wire-grid is reversed in its orientation, whereas the polarization perpendicular to it stays in the same direction. The overall effect is to create a differential phase-shift between orthogonal polarizations equal to 180 degrees. The rotation of the plate causes modulation of the polarization.

Credit: Giampaolo Pisano, Cardiff University

The new work is part of a multi-institutional collaboration funded by the European Space Agency's (ESA) Technology Research Program to develop technologies necessary for future experiments such as the proposed Cosmic Origins Explorer satellite mission program. This space mission aims to acquire high precision, full-sky maps of the cosmic microwave background - the relic emission that survived since the Big Bang.

Cosmic microwave background has been the subject of intense investigation since its discovery about 50 years ago. Recent years have seen an increased focus on the polarized components of this microwave background - in particular a component called B-mode, which is thought to hold the key to information about primordial gravitational waves and the physical processes that occurred very early in the history of the universe.

In The Optical Society (OSA) journal Applied Optics, the researchers demonstrated a new type of polarization modulator based on a magnetic mirror. The new device could overcome a major challenge to detecting the B-mode polarization -- the ability to modulate microwave polarization across a broad frequency range. Broadband operation is necessary to spectrally discriminate the extremely faint B-mode polarization from the foreground radiation of other astrophysical sources.

"We, like others, have been working for over two decades on the development of technologies that would enable the detection of the B-mode polarization," said Giampaolo Pisano, Cardiff University, UK, first author of the paper. "This has proven to be a challenging problem because only a tiny part of the overall signal exhibits this polarization."

Developing the technology

A key component for detecting B-mode radiation is a half-wave plate, a device used to modulate the polarization of electromagnetic radiation. Rotating the half-wave plate causes the polarization of the radiation to also rotate, creating an oscillating pattern that can be distinguished from the constant signal of unpolarized radiation.

Previous implementations of these half wave plates have resulted in inherently narrowband devices due to either the optical properties of available materials or the design used. Operation over a wide range of wavelengths is crucial to distinguishing B-mode polarization originating from the early universe from signals originating from other sources.

"Most of the effort in technology development has been aimed at making optical components that work over larger bandwidths," said Pisano. "A device that covers a wide frequency range would greatly enhance the performance of complex space-borne instrumentation."

In the new work, Pisano and his colleagues tried a completely new approach that uses metamaterials - manmade materials engineered with features not found in natural materials - to create a magnetic mirror that they combined with a polarizing wire grid.

"Metamaterials enabled us to invent a material with the characteristics we needed," said Pisano. "Because the approach we used is new, it allowed us to overcome the frequency range limits that other researchers have faced."

Their new method takes advantage of the fact that the reflection from an artificial magnetic surface will be out of phase from that reflecting from a perfect electric conductor, or metal. Adding the wire grid to the magnetic mirror allows one polarization to "see" the metal grid, while orthogonally polarized radiation reflects off the magnetic mirror. The resulting device can alter polarization over a large microwave frequency range.

The prototype device demonstrated in the paper operates from about 100 to 400 gigahertz with more than 90 percent efficiency, meaning that less than 10 percent of the signal was lost. The researchers say that with some minor adjustments, they expect to achieve even greater bandwidth and higher efficiency.

Getting ready for space

At 20 centimeters across, the prototype device is a miniaturized version of the one that could ultimately be needed for the Cosmic Origins Explorer satellite. The researchers are now working to develop a half-meter version, with the ultimate goal of developing a final device more than a meter in diameter. Making such a large device with the needed precision will require new facilities and new methods for handling the device during the various manufacturing steps, developments that the researchers say will likely be as difficult as developing the initial concept.

"Now that we've demonstrated the concept, we need to perform space qualification tests to demonstrate its ruggedness for a satellite launch," said Pisano. "We also need to deploy it in ground-based B-mode detection instruments to demonstrate it usability in the field."

###

Paper: G. Pisano, B. Maffei, P.A.R. Ade, P. de Bernardis, P. de Maagt, B. Ellison, M. Henry, M.W. Ng, B. Schortt, C. Tucker, "Multi-Octave Metamaterial Reflective Half-Wave Plate for Millimetre and Sub-Millimetre wave Applications," Applied Optics, 55, 10255-10262 (2016). DOI: 10.1364/AO.55.010255

About Applied Optics

Applied Optics publishes in-depth peer-reviewed articles emphasizing applications-centered research in optics. Published three times each month, Applied Optics reports significant practical applications of optical science and technology, photonics, lasers, information processing, sensing and environmental optics. It is edited by Ronald Driggers, St. Johns Optical Systems, USA. For more information, visit Applied Optics.

About The Optical Society

Founded in 1916, The Optical Society (OSA) is the leading professional organization for scientists, engineers, students and business leaders who fuel discoveries, shape real-life applications and accelerate achievements in the science of light. Through world-renowned publications, meetings and membership initiatives, OSA provides quality research, inspired interactions and dedicated resources for its extensive global network of optics and photonics experts. For more information, visit osa.org/100.

Media Contacts:
Rebecca B. Andersen
The Optical Society
randersen@osa.org
+1 202.416.1443

Joshua Miller
The Optical Society
jmiller@osa.org
+1 202.416.1435

http://www.osa.org 

Joshua Miller | EurekAlert!

More articles from Materials Sciences:

nachricht Beyond conventional solution-process for 2-D heterostructure
22.06.2018 | Science China Press

nachricht Graphene assembled film shows higher thermal conductivity than graphite film
22.06.2018 | Chalmers University of Technology

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Graphene assembled film shows higher thermal conductivity than graphite film

22.06.2018 | Materials Sciences

Fast rising bedrock below West Antarctica reveals an extremely fluid Earth mantle

22.06.2018 | Earth Sciences

Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View

22.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>