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ARGOS - The laser guide star for the LBT


 .MPE . Infrared Astronomy . Projects . ARGOS


Science Case












Beams on LBT Advanced Rayleigh guided Ground layer adaptive Optics System
Advanced Rayleigh guided Ground layer adaptive Optics System

The ARGOS projects will equip the LBT, the Large Binocular Telescope, with an up to date laser guide star and wavefront sensing facility. ARGOS will utilize multiple pulsed lasers to generate artificial guide stars. A total of six laser guide stars will be used to correct the ground layer turbulence above each of the LBT mirrors. The primary goal of the facility is to correct the atmospheric turbulence induced distortions, thus enhancing the imaging and spectroscopic capabilities for LUCIFER over a wide field of view. In contrast to usual single conjugated adaptive optics, ARGOS does not reach to the diffraction limit of the telescope. But it will be capable to reduce the seeing by a factor of 2-3 over a 4 arcmin field of view.

The system consists of:

  • Laser systems, each of them containing three powerful pulsed green lasers
  • Beam expanders to enlarge the lasers to a 40cm diameter and project them to sky
  • Wavefront sensors to detect the backscattered light from the beacons
  • The adaptive optics control of LBT’s deformable secondary mirrors


Final laser system assembly (Apr. 2012)
We started to assemble and test the laser boxes.
Working on the laser box
Laser stars on the ceiling
While the DX laser box (background) is already in test, we work on the SX box.
First light! (of the alignment lasers on the ceiling...) High power test will follow soon.
The central spot is the sodium dummy laser.

Laser box software test (Nov. 2011)
With this test setup we checked how the instrument software, which is still under development, is working with a complex system like our laser box. Here it has to handle several motors, cameras, diagnostic systems, safety systems and of course the laser itself.
Laser system
Laser system
More ARGOS installations on the telescope (Aug. 2011)
The installation of the calibration swingarm is in progress. Seen on the LBT Live views.

LBT without swingarm LBT with swingarm
LBT without swingarm.
LBT with the first ARGOS swingarm on SX C-ring extension.
Secon swingarm installation
operational swingarm
Installation of the second swingarm.
Operational swingarm.
We thank and congratualte all the team for this great work!
ARGOS consortium meeting Firenze (Mar. 2011)
Consortium meeting Florence 2011
Almost the complete ARGOS team came to Acetri, Florence to join the regularly consortium meeting.
In the background, but unfortunately not visible here, is Galileo Galilei's house.

ARGOS telescope simulator (Dec. 2010)
The telescope simulator will help us to integrate and test our laser system or other sub-systems. It is capable to rotate 2 laser boxes (6 lasers), together with 4 electronic racks by 0-90.
And a merry Christmas to everybody!
Telescope Simulator 45
Simulator and Team
Tilted telescope simulator.
Team members after the delivery: Hans, Sebastian, Julian, Matthias and Thomas.
Installation of the first Argos Platforms (Sept. 2010)
SR: "During the last week the first pieces of Argos have been brought to mount Graham and are now installed to the telescope. As first infrastructure two rigid platforms for the laser systems surrounded by access platforms and mounts for the racks are now fixed in between the windbraces. Thanks to the careful design, the excellent campaign planning, our nice and enthusiastic installation team and a friendly support by LBTO, the platforms where installed smoothly, in time and perfect position.
Many thanks to the installation team: Hans, Matthias D, Mathias H & Stefan! "
The successful installation team (L to R: Stefan Huber, Mathias Honsberg, Hans Gemperlein; Matthias Deysenroth.)
The 2 platforms and a dummy electronics box are installed to the LBT.
Cutting Steel (Aug. 2010)
Launch Platform Fast Photodiode
The laser launch and supply platforms were manufactured and accepted. Now they will be painted, shipped and installed to the LBT.
In the meanwhile the first electronics parts were manufactured. Here the fast photodiodes, used for the laser diagnostics.
Hardware is proceeding (May 2010)
PNCCD 2.Generation
Microgate HVC
pnCCD 2. genreation (left). While the first test system (right) was cooeld by a Stirling cooler and an always running vacuum pump, the new one is cooled by peltier elements. This was a big step towards the final design.
The Microgate BCU with a high coltage controller. This will capture the the data of our wavefront sensor and control a tip-/tilt-piezo mirror to stabilize the incoming light.
(Picture shows a similar device)

Final Design Review (27.-28. Mar. 2010)
The Argos final design review just has finished with the panels judgement that we have 'passed' !
FDR Review ARGOS and LUCIFER team
The Final Design Review in Tucson.
Close co-operation between ARGOS and LUCIFER.
28 documents, 844  pages.
Our documents for the Final Design Review are prepared and ready for delivery (Mar. 2010)
FDR documentation FDR documents

Testing a lot of our final stuff: 3 lasers on one heat exchanger, the water cooled power meter and some small electrical devices.
All operated on the 230VAC/50Hz to 120VAC/60Hz converter and on a tilting bench. (Feb. 2010)
3 laser beams on one power meter
Question: How much is the average power output of one laser? 3 Lasers shooting on one powermeter (the small box on the upper border)
Oh yes, there will be light (Feb. 2010)
3 Lasers 6 Laser heads
First test of 3 lasers on one heat exchanger. Already operated with 120V/60Hz. Ready for the telescope: six lasers for six stars.
... and the ARGOS lasers were delivered (Nov. 2009)
Lasers are delivered
#1 is operating
some of the boxes #1 was started up by its proud parents. Output power is ~18.7W, pulsewidth ~26ns. Weight is about...
The ARGOS Lasers are ordered (July 2009)
(Images from the manufacturer)
InnoLas Nanio InnoLas Nanio
The InnoLas nanio series NANIO 532-18-Y
532nm, 18W at 10kHz

peltier test carrier pnCCD camera head
While the development of the peltier element based cooler for the wavefront sensor detector is in progress.... ...a system of the pnCCD arrived at our lab in Garching. (June 2009)
Visit of the Solar Tower at INAF during ARGOS consortium meeting in May 2009.
inspecting AGW unit it works!
LBT's adaptive secondary (about 15m above)
 is tested here with the AGW unit.
Demonstration of the adaptive secondary. It works!
Dinner at Neuwirt

ARGOS Preliminary Design Review 17./18. Feb. 2009
left->right: Bob Fugate, Richard Myers, Enrico Fedrigo
Not shown: Francois Rigaut
PDR Dinner

Ks image of NGC 1569 taken during commissioning with LUCIFER.

Lucifer installed on derotator
Ks image of NGC 1569 taken during commissioning with LUCIFER,
end 2008 / beginning 2009
Lucifer installed on the SX derotator, Jan. 2009


The ARGOS consortium is assembled from the LBT partners. Please see the dedicated web page.

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