The VLT Adaptive Optics Facility

1. The VLT Adaptive Optics Facility R. Arsenault, P.-Y. Madec, W. Hackenberg, J. Paufique, S. Stroebele, J.-F. Pirard, E. Vernet, D. BonacciniCalia, I. Guidolin, M. Quattri, R. Guzman, B. Buzzoni, M. Comin, C. Dupuy, A. Silber, J. Quentin, G. Igl, L. Taylor, J. Argomedo, P. Jolly, A. Manescau, R. Stuik, M. Downing, J. Reyes, A. Jost, M. Duchateau, N. Hubin, A. Glindemann, P. Amico, M. Lelouarn, J. Kolb, S. Tordo, E. Fedrigo, R. Donaldson, C. Soenke, R. Conzelmann, B. Delabre, M. Kiekebusch, J.-L. Lizon, P. La Penna, L. Jochum 20th Anniversary of AO at ESO

2. AOF: why…what… • To provide improved observing conditions for UT4 Instruments by delivering • A better seeing in a Wide Field of View • Diffraction limited images in one direction • with as constraints • Not to degrade the Instruments throughput/emissivity • High sky coverage • To turn-out UT4 in an Adaptive Telescope • To replace M2 by a Deformable Secondary Mirror • To provide a Multi-Laser Guide Star Facility • To build two post-focal LGS/NGS WFS Modules 20th Anniversary of AO at ESO

3. HAWK-I and MUSEthe two (first) customers of AOF • HAWK-I, a Wide FoV IR Imager (0.9 – 2.5 mm) • 7.5 x 7.5 arcmin2 FoV – 0.1 arcsec pixel size • Requirement towards AOF, in K bands • Gain of ≈2 in EE in 0.1 arcsec (seeing reducer: x0.8) • MUSE, a visible 3D Spectrograph (465-930 nm) • WFM • 1 x 1 arcmin2 FoV – 0.2 arcsec spaxel size • Requirements towards AOF: gain of ≈2 in EE in 0.2 arcsec • NFM • 7.5 x 7.5 arcsec2 FoV – 0.025 arcsec spaxel size • Requirements towards AOF: 5% to 10% Sr at 650 nm under 0.6 arcsec seeing 20th Anniversary of AO at ESO

4. AOF: how… • MUSE NFM and WFM requirements • Number of DSM actuators > 1000 (1170 final) • Number of WFS subapertures > 33x33 (40x40 final) • Control frequency ≈ 1 kHz • LGS brightness (at Nasmyth) 5 106 photons/m2/s • WFS camera RoN < 1 e-/pixel/frame • HAWK-I and MUSE WFM requirements • Number of LGSs 4 • HAWK-I requirements • LGS distance from opt. axis up to 6 arcmin 20th Anniversary of AO at ESO

5. AOF main subsystems GRAAL DSM GALACSI LGS Unit 20th Anniversary of AO at ESO

6. DSM/M2 Unit (MG/ADS/OAA) • Same functions and interfaces as the actual M2 Dornier • Optical diameter 1120 mm • Focus, centering, tilt/chop • Hub interfaces • 2 mm Zerodur thin shell, with magnets glued on • 1170 voice coil actuators • DSM response time 0.7 ms • Liquid cooled (1.5 kW) • Delivery date end 2011 20th Anniversary of AO at ESO

7. DSM development status 20th Anniversary of AO at ESO

8. 4 Laser Guide Star Facility • 4 identical LGS Unit, mounted on UT4 Center Piece • One 40 cm diameter Launch Telescope (TNO) • One Beam Control and Diagnostic System (ESO) • Control of focusing altitude (70 to 200 km) • Control of LGS position (0 to 6 arcmin from optical axis) • LGS jitter stabilization mirror (controlled by AO modules) • Safety devices (shutters) • Diagnostic tools (power meter, WFS, alignment camera) • One 20 W CW dual line laser (outsourced) • 18 W in D2a and 2 W in D2b lines (back-pumping scheme) • Compact, efficient, reliable and maintainable laser 20th Anniversary of AO at ESO

9. 4LGSF: development status FASORtronics Laser TOPTICA Laser Launch telescope (TNO) 20th Anniversary of AO at ESO

10. GRAAL: the HAWK-I AO Module • GLAO mode: seeing enhancer in 7.5 x 7.5 arcmin2 FoV • 4 LGSs located almost 6 arcmin from the opt. axis • No optics inserted in the HAWK-I scientific FoV 20th Anniversary of AO at ESO

11. GALACSI: the MUSE AO Module • WFM • GLAO mode: seeing enhancer in 1x1 arcmin2 FoV @ 750 nm • 4 LGSs located ≈1 arcmin from the optical axis • NFM • LTAO mode: 5% to 10% Sr in a 5arcsec diameter FoV @ 650 nm • 4 LGSs located ≈10 arcsec from the optical axis • (Almost) no optics inserted in the MUSE scientific FoV 20th Anniversary of AO at ESO

12. AOF: common critical components • SPARTA: real-time architecture for AO control • Inputs: 4 x (240x240 pixels / 1240 subap.) Shack-Hartmann • Outputs: 1170 commands • Control frequency: 1 kHz – latency: 400 ms • WFS measurement algorithm: WCoG • Control algorithm: Matrix Vector Multiplication 20th Anniversary of AO at ESO

13. SPARTA: development status GB Ethernet Switch RTC box Co-processing cluster 20th Anniversary of AO at ESO

14. AOF: common critical components • SPARTA: real-time architecture for AO control • Inputs: 4 x (240x240 pixels / 1240 subap.) Shack-Hartmann • Outputs: 1170 commands • Control frequency: 1 kHz – latency: 400 ms • WFS measurement algorithm: WCoG • Control algorithm: Matrix Vector Multiplication • WFS camera • 240x240 pixels – 1000 frames/s • High QE: > 80% @ 589 nm • RoN: < 1e-/pixel/frame 20th Anniversary of AO at ESO

15. WFS Cameras: development status E2V CCD 220 WFS camera head: first ESO prototype Ocam – test camera 20th Anniversary of AO at ESO

16. AOF: common critical components • SPARTA: real-time architecture for AO control • Inputs: 4 x (240x240 pixels / 1240 subap.) Shack-Hartmann • Outputs: 1170 commands • Control frequency: 1 kHz – latency: 400 ms • WFS measurement algorithm: WCoG • Control algorithm: Matrix Vector Multiplication • WFS camera • 240x240 pixels – 1000 frames/s • High QE: > 80% @ 589 nm • RoN: < 1e-/pixel/frame • ASSIST: the AOF test and calibration tool • Optical calibration of the DSM • Full system test of the AOF 20th Anniversary of AO at ESO

17. ASSIST: the AOF test bench • 2.5 arcmin unvignetted fov • Diffraction limited on-axis and stringent pupil imaging quality • Simulation of NGSs and LGSs (including elongation) • 3 phase screens at different altitudes • Simulation of VLT Nasmyth focus (f/15 – pupil at -16 m from focus) 20th Anniversary of AO at ESO

18. ASSIST: development status 20th Anniversary of AO at ESO

19. AOF on-sky: when… • Critical path: DSM and laser delivery • DSM end 2011 • Laser last one beginning 2013 • Tests of DSM, GRAAL and GALACSI in Garching • One year needed end 2012 • Installation of AOF at Paranal • Beginning 2013 (synchronized with laser delivery) • AOF first light 2013 20th Anniversary of AO at ESO