CFHT, Instruments, Imaging, AOB, Upgrade
PUEO NUI: High contrast imaging and visible AO
an upgrade of the CFHT Adaptive Optics
The proposal for the
upgrade to 104 electrode as submitted to SAC is available here. You can also download the SPIE 2002 paper describing the
upgrade, or click here for the PowerPoint
After the upgrade plan to 36 electrodes was deemed not ambitious enough,
some simulations were performed to study the potential and limits of
curvature sensing with high numbers of degrees of freedom. The results
of this study were presented at the "Beyond conventional adaptive
optics" conference, in Venice in 2001. The paper is available here.
The advantages are numerous, but most noteworthy are:
- Better image quality at short wavelengths (diffraction limit to H
- Strehl ratios up to 95% in K band, and improved image stability for
cornography, phase coronography and multi-wavelength imaging
- No degradation of image quality on faint objects, maximum perfomand
magnitude estimated at 7.
Currently the plan of the upgrade consists of the following steps:
- Demonstration of Fly-Eyes (replacing the APDs with a CCID-35
detector for the wavefront sensing) with the current 19 electrode
system. Even though the new detector will have a 2e- read noise, the
overall performance should be improved due to the QE (increased from 40%
- Identifying mirror vendor, lenslet array and real time computer
solutions, to build a lab demonstrator/test bench.
- Installing the new components into AOB, and integration off the
telescope with an estimated down time of hopefully 6 months to a year.
- Integration on telescope.
- Start thinking about LGS! (See SPIE paper...)
Created 26 January 00.
Modified 10 October 02.
Page maintained by Olivier Lai.
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