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Sodium Laser Guidestar Page

Sodium wavelength lasers are critical to the next generation of adaptive optics for ground-based astronomical telescopes. Important issues are:

Summary of Sodium Laser Guide Stars now "On-the-Sky"

(in no particular order)
Numbers in the table are approximate or typical. See the references for more details. Please use standard Guidelines in reporting return measurements

Facility Principal Investigators Laser Maker and Type Return / Watt (Details) Average Power Spot Size (apparent) Pulse & Spectral Format Web Link
Lick Mt. Hamilton Claire Max, Don Gavel LLNL Tunable Dye 10 ph/s/cm2/W 12 W 2 arcsec 100 ns, 11 kHz, 2 GHz EO modulated SPIE paper
Starfire Optical Range Bob Fugate, Craig Denman SOR Solid state, resonant sum-frequency generator 100 ph/s/cm2/W seasonal average 50 W seeing limited 1.4-3 arcsec (site has r0=7.8cm avg) CW 10 kHz line SPIE article and Craig Denman's talk at the Nov 2006 LaserWorkshop
W. M. Keck Observatory Peter Wizinowich LLNL Tunable Dye 10 ph/s/cm2/W 12-15 W 1.8" x 2.3" (average stacked) 100 ns, 25 kHz, 2 GHz EO modulated K2LGSAO web and SPIE'06 paper (Table 1)
Palomar Richard Dekany, Ed Kibblewhite, Antonin Bouchez University of Chicago Solid state sum-frequency mode-locked 60-80 ph/s/cm2/W 6-8 W 1.8" FWHM arcsec in 1.0 arcsec V-band seeing 1 ns micropulse inside 300 microsec bursts at 300 Hz repetition rate
Subaru Masanori Iye, Yutaka Hayano solid state sum-frequency To be measured 5.4 W at output of laser To be measured ~0.8 ns pulses, 143MHz rep rate, mode-locked (quasi-CW) 1.7GHz bandwidth
Gemini North Francois Rigaut, Celine D'Orgeville Lockheed-Martin Coherent Technologies diode-pumped solid state 1.06+1.32micron sum-frequency laser 27photons/cm^2/s/W: photon return at the primary mirror of the Gemini North telescope, per laser power projected to the sky out of the LLT, with linear polarization (Note: later observed ~30% increase with circular polarization at zenith) Photon return measurement made in May 2005, during season of lowest sodium abundance, with ~6W projected to the sky (Note: as of May 2009, typical is ~12 W at the ouput of the laser, ~11W projected to the sky, with BTO+LLT throughput ~90%) 1.3 arcsec 0.7 ns pulses, 76 MHz rep rate, CW mode-locked, 550MHz bandwidth Altair LGS instrument page and laser commissioning news
Very Large Telescope Domenico Bonaccini Calia Max Planck Institutes Tunable Dye 54 ph/s/cm2/W 10 W 1.25 arcsec CW 3x10 MHz separated by 110MHz SPIE article on first light

New Laser Development

Institution Principal Investigators Sponsor Laser Type Progress Reference
Lockheed-Martin Coherent Technologies Allen Tracy, Allen Hankla AODP Sum frequency solid state, 1319nm+1064nm into PPSLT, modular pulse format 1.5 W / 10 W goal SPIE article
Lawrence Livermore National Laboratory Dee Pennington, Jay Dawson AODP and CfAO Sum frequency fiber, 1583nm+938nm into PPSLT, modular pulse format, 500 MHz linewidth 3.5 W / 5-10 W goal SPIE article
Lockheed-Martin Coherent Technologies LMCT: Ian Lee; Keck: Sean Adkins; Gemini: Celine d'Orgeville NSF/AURA for Keck I/Gemini South telescopes resp. Sum frequency solid state, 1319nm+1064nm into LBO, 0.3 ns pulse every 12 ns (CW mode-locked) As of Sep. 2009: 40W Keck laser and 50W GS laser demonstrated in the lab, Keck laser passed FAT at LMCT and delivered to WMKO, GS laser pending FAT at LMCT SPIE article
European Southern Observatory Domenico Bonaccini Calia, Yan Feng, Luke Taylor ESO Frequency-doubled 1178 nm narrow-band Raman fiber amplifier Demonstrated 50 W cw @ 589 nm Optics Express paper Frontiers in Optics 2009, postdeadline paper

Interesting Topics



Name Institution e-mail
Don Gavel UC Santa Cruz