Download JRA2 Fast Optical Detectors for AO

JRA2 – Fast Detectors for Adaptive Optics
The participants will attempt to define, fabricate and fully
characterize the best possible detector working at visible
wavelengths which is suitable for wavefront sensors in Adaptive
Optics (AO) systems. This Joint Research Activity is closely linked
to JRA1 - Adaptive Optics. This will ensure that this detector
development follows the AO requirements in terms of wavefront
sensing detectors. The detector format should be 256x256 pixels,
the frame rate must be very fast (up to 2 kHz) while the readout
noise must be kept extremely low (typically below 3e-).
Fast Detector for AO: the
need
The next generation of Adaptive Optics
systems for 8 to 10-m class telescopes
will require an increased number of
degrees of freedom, which will increase
the number of actuators required
typically by a factor of 5 to 10. Existing
CCD’s will not allow production of the
corresponding wavefront sensors. The
success of such new AO concepts will
therefore strongly depend on new
developments in the field of visible
wavefront sensor detectors, both in
terms of usable number of pixels and
increased sensitivity.
Detector technologies and
specifications
A non-exhaustive list of possible
detector technologies is:
1.Single direction or split frame transfer
CCD with a large number (up to 512) of
output amplifiers that are read out at
moderate to low speed. A possible
output amplifier configuration is one
amplifier per detector column.
2.Single direction or split frame transfer
CCD with a small number of output
amplifiers that are read out at high
speed. To meet low read noise
requirements, the devices will use
special techniques such as electron
multiplication CCD technology to amplify
the signal and reduce effective output
amplifier read noise.
3.Direct readout device (hybrid, CMOS)
where the detector will be coupled to a
readout multiplexer.
A Call For Tender was started in July
2004 in order to choose the detector
manufacturer. Now this choice has been
made, the detector is being fabricated
and fully tested, at first by the
manufacturer and soon after by the
partners of the JRA2. The main output
of the JRA2 will be the test report of the
detector produced in the context of AO
systems for 10m class telescopes
Participants
c/o ESO: the NAOS visible wavefront sensor
The 7 collaborating organisations are:
• Laboratoire d’Astrophysique de
Grenoble
• Laboratoire d’Astrophysique de
Marseille
• Observatoire de Haute Provence
• Instituto de Astrofisica de Canarias
• ESO
• ONERA
• Observatoire Midi-Pyrénées
Block diagram of a simple AO system
OPTICON is funded by the European Commission under Contract RII3-CT-2004-001566
Our Mission
Visible detectors fully
matching the requirements of
Adaptive Optics wavefront
sensors for 10m class
telescopes do not yet exist:
current detectors have frame
rates which are too slow and
which are too noisy for the
second generation of AO
systems.
The visible detectors
developed by this JRA will be
dedicated to AO applications.
The scalability of these
detectors for ELT AO systems
will be taken into account.
Contact
Philippe Feautrier
JRA2 Principal Investigator
Laboratoire d’Astrophysique
Observatoire de Grenoble
Domaine Universitaire
414 rue de la piscine, BP53
38040 Grenoble Cedex 9
France
Telephone: +33 (0)4 76 63 59 81
E-mail:
[email protected]
OPTICON - The Optical
Infrared Coordination Network
for Astronomy