The hunt for Earth-like planets around distant stars could soon become a lot easier thanks to a technique developed by researchers in Germany.
In a paper published today, 18 February, in the Institute of Physics and German Physical Society’s New Journal of Physics, the team of researchers have successfully demonstrated how a solar telescope can be combined with a piece of technology that has already taken the physics world by storm—the laser frequency comb (LFC).
It is expected the technique will allow a spectral analysis of distant stars with unprecedented accuracy, as well as advance research in other areas of astrophysics, such as detailed observations of the Sun and the measurement of the accelerating universe by observing distant quasars.
The LFC is a tool for measuring the colour — or frequency — of light, and has been responsible for generating some of the most precise measurements ever made. An LFC is created by a laser that emits continuous pulses of light, containing millions of different colours, often spanning almost the entire visible spectrum.
When the different colours are separated based on their individual frequencies — the speed with which that particular light wave oscillates — they form a “comb-like” graph with finely spaced lines, or “teeth”, representing the individual frequencies.
This “comb” can then be used as a “ruler” to precisely measure the frequency of light from a wide range of sources, such as lasers, atoms or stars.
In their study, the researchers, from the Max Planck Institute of Quantum Optics, the Kiepenheuer Institute for Solar Physics and the University Observatory Munich, performed an analysis on the Sun by combining sunlight from the Kiepenheuer Institute’s solar telescope in Tenerife with the light of an LFC. Both sources of light were injected into a single optical fibre which then delivered the light to a spectrograph for analysis.
Lead author of the study Rafael Probst, of the Max Planck Institute of Quantum Optics, said: “An important aspect of our work is that we use a single-mode fibre, which takes advantage of the wave nature of light to enable a very clean and stable beam at its output. This type of fibre is quite common in telecom and laser applications, but its applications in astronomy are still largely unexplored. The LFC at the solar telescope on Tenerife is the first installation for astronomical use based on single-mode fibres.
“Our results show that if the LFC light and the sunlight are simultaneously fed through the same single-mode fibre, the obtained calibration precision improves by about a factor of 100 over a temporally separated fibre transmission.
“We then obtain a calibration precision that keeps up with the best calibration precision ever obtained on an astrophysical spectrograph, and we even see considerable potential for further improvement.”
Indeed, the researchers envisage using the new technique to not only study the star at the centre of our solar system, but stars much further away from us, particularly to find Earth-like planets that may be orbiting around them.
When a planet orbits a star, the star does not stay completely stationary, but instead moves in a very small circle or ellipse. When viewed from a distance, these slight changes in speed cause the star’s light spectrum to change a process known as a Doppler shift.
If the star is moving towards the observer, then its spectrum would appear slightly shifted towards the blue end of the spectrum; if it is moving away, it will be shifted towards the red end of the spectrum.
The researchers believe that an LFC would allow them to measure these Doppler shifts much more accurately and therefore increase the chances of spotting Earth-sized, habitable planets.
With conventional calibration techniques, the researchers state that they could measure a change in speed of roughly 1 m/s over large time periods; an LFC could enable measurements with an accuracy of 1 cm/s.
“In astronomy, LFCs are still a novelty and non-standard equipment at observatories. This however, is about to change, and LFC-assisted spectroscopy is envisioned to have a flourishing future in astronomy. Our present work shows how future astronomical LFCs could be utilized,” Probst concludes.
The work is a collaboration comprising the Max Planck Institute of Quantum Optics in Garching, Germany, the Kiepenheuer Institute for Solar Physics in Freiburg, Germany, and the University Observatory Munich in Munich, Germany. Among the contributors are guest scientists from the National Astronomical Observatories of China in Beijing. Menlo Systems GmbH in Martinsried, Germany, is part of the collaboration as an industrial partner.
[IOP Publishing press release]
Max Planck Institute of Quantum Optics
Hans-Kopfermann-Str. 1, 85748 Garching, Germany
Phone: +49 (0)89 / 32 905 - 509
Dr. Ronald Holzwarth
Max Planck Institute of Quantum Optics
Hans-Kopfermann-Str. 1, 85748 Garching, Germnay
Phone: +49 (0)89 / 32 905 - 255
Prof. Dr. Theodor W. Hänsch
Professor of Experimental Physics,
Director at Max Planck Institute of Quantum Optics
Hans-Kopfermann-Straße 1, 85748 Garching, Germany
Phone: +49 (0)89 / 32 905 - 712
http://iopscience.iop.org/1367-2630/17/2/023048 (Link to paper download)
Dr. Olivia Meyer-Streng | Max-Planck-Institut für Quantenoptik
Further Improvement of Qubit Lifetime for Quantum Computers
09.12.2016 | Forschungszentrum Jülich
Electron highway inside crystal
09.12.2016 | Julius-Maximilians-Universität Würzburg
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine