Mt. Palomar Mountain
35899 Canfield Rd
Palomar Mountain, CA 92060
Click here for a layout of the Mount Palomar Adaptive Optics Optical Bench.
Partial optical layout of the Palomar AO system. The light enters the system at the 45 degree fold mirror marked "From telescope" which diverts the F/15.7 beam to a collimating off-axis parabolic mirror (OAP1), next the collimated beam hits the fast steering mirror (FSM), followed by the deformable mirror (DM). A fold mirror, used for packaging redirects the light to a second OAP (OAP2), which relays the beam back to F/15.7 and to the dichroic. Light with a wavelength longer then 1050 nanometers passes through the dichroic to a fold mirror and the current science camera (PHARO). Shorter wavelength light bounces off the dichroic to a second fold mirror. The pairs of mirrors provide method for star selection and pupil steering. The light then reflects off a field stop and into the Shack-Hartmann camera.
The Palomar Adaptive Optics System (PALAO), built by Jet Propulsion Laboratory , corrects for the atmospheric blur of astronomical targets caused by turbulence in the Earth's atmosphere. Science images are obtained using the Palomar High Angular Resolution Observer (PHARO), design and built by Cornell University.
Using a Xinetics, Inc. 349/241 active-element deformable mirror, the system compensates for the pathlength errors caused by index of refraction variations caused by thermal inhomogeneiti es in the atmosphere. Wavefront information is obtained using a Shack-Hartmann sensor based upon a SciMeasure A nalytical Systems, Inc. fast-frame, low-noise camera. These commercial partners are a ls o developing new high-actuator-density mirrors and advanced cameras based on EEV , Inc. technology, respectively.
The instrument mounts at the Cassegrain focus underneath the 5m diameter telescope at Palomar Mountain. Because of it's inherently larger diameter, the 5m telescope, when adaptively corrected, provides approximately twice the imaging resolution as the 2.4 meter diameter Hubble Space Telescope, from the ground.
The Palomar AO System, however, requires a bright natural guide star within the scientific field of regard, in order to derive reliable information on the instantaneous status of the turbulent atmosphere.
For more detailed technical information on the Palomar AO System, click here.
For a tutorial introduction to adaptive optics, try this link.