“First light” of the new laser guide star technology at the Allgäu Public Observatory (ESO/T. Kasper (AVSO)).
“First Light” for TOPTICA’s Laser Guide Star Technology
June 22nd, a novel approach to laser guide star technology, developed by TOPTICA jointly with ESO and the Canadian company MPB Communications has had its “first light” at the Public Observatory in Ottobeuren, Germany. The laser system generates a narrow-band 20 Watt cw beam at 589 nm and is designed to resonantly excite the sodium atoms in the Earths mesosphere at 90 km distance from the ground. In the future, this “guide star technique” (SodiumStar) will serve as a beacon to enable the so-called adaptive optics system of a large telescope, that corrects for wavefront-distortions induced by turbulences in the atmosphere of the Earth.
In July 2010, TOPTICA was awarded a contract for the development and final installation of four Sodium guide star lasers by the European Southern Observatory (ESO). The “Wendelstein laser” now is the first publically visible result of the close cooperation between the partners. It is the first on-sky-installation and will be operational at the Allgäu Public Observatory for a few months, and is attracting quite a bit of public awareness. ESO will use this laser in the following weeks to conduct atmospheric measurements, validating the general set-up in operation and obtaining more detailed information about subtleties of the sodium distribution in the mesosphere. In particular, the excitation efficiency under the varying earth magnetic field will be studied in order to maximize the LGS return signal during typical observation conditions.
TOPTICA has developed the laser guide star based on its core technology combined with a novel narrow-band Raman fiber amplifier technology (EFRA), that was initially invented by ESO’s laser group. The technology has been licensed in order to amplify a spectrally narrow and tunable diode laser seed at 1178 nm to about 35 Watt of optical power. Subsequent efficient frequency conversion yields more than 20 Watt output power right at the sodium resonance (589 nm) with a line width of less than 5 MHz. The approach is overcoming multiple previous approaches that were, to say the least, difficult to implement on the top of a mountain, where typical earth-based telescopes are situated. In 2013, four of these TOPTICA laser guide star are to be installed at the Very Large Telescope (VLT) of the ESO at Paranal, Chile.
More information can be found at ESO: http://www.eso.org/public/announcements/ann11039/
Information about Laser Guide Stars:
- Laser Guide Star / Astronomy
- Video: Create your own star
- Video: TOPTICA's yellow laser - Innovation Award Honorable Mention
- Article: Reaching for the stars (Laser+Photonics Made in Germany + Austria + Swizerland 2011, p. 28)
- Article: Schärfer sehen mit adaptiver Optik (Optik&Photonik, Volume 6, Issue 1, pages 51-55, February 2011)
