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Palomar Adaptive Optics Status. Viswa Velur b, c , Mitchell Troy a , Richard Dekany b , E.J. Kibblewhite c
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Palomar Adaptive Optics Status Viswa Velurb, c, Mitchell Troya, Richard Dekanyb, E.J. Kibblewhitec Gary Bracka, Matthew Brittonb, Rick Burrussb, Steve Guiwitsa, Jeff Hickeyb, Cathy Oharaa, Dean Palmera, Jennifer Robertsa, Fang Shia, Hongwu Renb, Bob Thickstenb, Thang Trinha, Tuan Troung a, Kent Wallacea a Interferometry and Large Optics, JPL b Caltech Optical Observatories, California Institute of Technology c Fermi Inst., Univ. of Chicago
Palomar Adaptive Optics Overview Closed Loop FWHM 0.090 arcsec Strehl ~80% at K 165nm Wavefront Error Open Loop FWHM ~0.70 arcsec Strehl ~2% at K Log Stretch • Facility instrument at Palomar observatory for last ~4 years • The most requested instrument at Palomar • Natural guide star AO system • 16x16 subapertures • Bright guide star Strehls as high as 80% at 2.2 mm • Maximum frame rate 2000Hz (<7e- read noise) • Limiting magnitude ~13.5mV, 10-15% Strehl at 2.2 mm • Read noise 3.5e- at < 500 fps • Science Camera • J, H, and K imaging and 0.025 and 0.040 arcseconds/pixel • Coronagraph 0.41 and 0.91 arcsecond spot • J, H and K spectra at R~1500
Palomar AO Performance(Comparison to perfect and simulations) Log Stretch 3 arcseconds Simulated AO Image RMS wavefront = 130nm Strehl=0.86 PALAO image on sky RMS wavefront=165nm Strehl= 0.80 (10 images have S = 0.75 +/- 0.02) SimulatedPerfect Image(using Arroyo (Caltech)) • Wavelength Ks (2.145 mm, width=0.3mm) • r0 (0.5m) = 11cm • 5 second exposures • Excellent agreement with simulations! • Difference of 100nm is consistent with AO calibration errors
Palomar AO Program • 4-channel 16x16 SHWFS tomograph will be completed Fall 2004 • Implement Na LGS • Laser now at Palomar (since May 2004) • Plan to propagate laser before end of 2004 • Closed loop operations in 2005 • 100 nm wavefront demonstration in 2005 • Off-Axis unobscured 1.2 meter pupil • Actuator spacing 8 cm • Head-to-head Na LGS return tests 2006+ • CSFL vs. CW fiber laser vs. CW solid-state (tentative) • PALMAO-3000 (proposed to NSF) • Plans to implement a N=64 actuator DM at Palomar
CSFL specification • CSFL designed to be a mode-locked pulsed laser with a 1.2 GHz line-width to match the sodium absorption in the mesosphere. • Current power levels: • 1064-nm laser power = 14W • 1320-nm laser power = 8W • 589-nm laser power = 3.5W (stable over >> 50 hrs) • Expected 589-nm power (on sky): > 5W • 1W of this spectral format has been shown to produce a ~9.5 Mv star. • CSFL includes diagnostics for line-width, beam quality, power, sodium atom absorption.
CSFL in action 1064nm Beam quality, M2= 1.1 589-nm light Rectangular pulse Mode-locked pulses
Components of BTO F #2 system Trolley and laser launch telescope
Summary and future efforts: • We now have working source lasers at Palomar. Sum-frequency module nearly (re-)assembled after shipping • The BTO system will be tested in July 2004 • Coude infrastructure development to house multiple lasers in place by Aug 2004 • We hope to propagate the laser in Oct 2004 • We plan to prototype a Mach III laser head