Quantum laser comb technology opens up a new future for spectrophotometers

The astronomical tools needed to answer crucial questions such as searching for planets like Earth or how the universe expands, have just taken a step closer to the first proof at a systematic telescope Determine the new size for the correct optical recorder.

This method uses a Nobel Prize-winning technology called "laser frequency comb" and was published in Science this week.

"It seems that we are on the way to accomplishing one of astronomers' dreams," said Theodor Hansch, director of Max Plank (MPQ) Quantum Optical Institute in Germany. Hansch, along with John Hall, was awarded the 2005 Nobel Prize in Physics for work including "quantum comb" technology.

Astronomers use spectral recorders to spread light from space objects into color components or frequencies in the same way that a rainbow is formed from sunlight. These machines can then measure the velocities of stars, galaxies and quasars, search for planets around other stars or study the expansion of the universe.

Such a laser comb serves as a measure of sizing for new spectrophotometers with high precision needed to search for Earth-like planets and to measure the expansion of the universe in the future. .

A spectrophotometer must be accurately calibrated so that light frequencies can be accurately measured. This is similar to the one we need to accurately measure the length. In the present case, laser technology provides a ruler to measure colors rather than distances with a high degree of accuracy.

These new spectrophotometers will be needed in experiments planned for the future of the European super-large telescope (E-ELT), designed by ESO, the Southern European observatory. In fact, these spectrophotometers must be accurate to 1 part 30 billion - equivalent to measuring the Earth's diameter to 1 millimeter.

"We will need something more than what current technology can allow and that is the" quantum comb "technology. It is worth withdrawing the exact type of requirement of 1 cm / s, equivalent to "the money plane" of a high resolution spectrophotometer, "explained a member, Constanza Araujo-Hauck, from ESO.

After successful tests in the MPQ laboratory in 2007, the group continued to succeed in testing a first tool using "quantum combs" on the Vacuum Tower Telescope in Tenerife. on March 8, 2008, measuring the Sun's spectrum in infrared radiation. This result is impressive and the technology also promises to achieve the precision needed to study thorny astronomical questions.

"In tests in Tenerife, we have achieved the best possible accuracy. We continue to make this system more flexible and develop it further," said member Tilo Steinmetz from Menlo. Systems GmbH, a subsidiary from Max Plank Institute, was established to commercialize this "quantum comb" technology.

A version of this system is being built for HARPS planet finder on ESO's telescope at La Silla center in Chile before being considered as the future of this tool.

One of the ambitious projects along with E-ELT is CODEX, which aims to measure the expansion of the recently discovered universe directly by monitoring the speed of distant galaxies and quasars in about 20 years. This allowed astronomers to test Einstein's theory of relativity, or dark matter.

"We have to measure the movements of galaxies as far as a few centimeters per second and monitor them for a few decades," said ESO member Antonio Manescau.

Astronomers also use spectroscopes to hunt planets orbiting other planets by searching for the subtle movements of the star that these planets move around. To be discovered by current technology, these planets must be quite large or close to the host star, like the Earth. A more accurate spectrophotometer will allow astronomers to search for planets with Earth-like properties.

The article is provided by reader Tran Ba ​​Long
Email:longfigo.1988@gmail.com