Fast detectors (for E-ELT AO)

1. Fast detectors (for E-ELT AO) Philippe Feautrier INSU/CNRS-LAOG Fast detectors

2. Highlights of the FP6 JRA2: Fast detectors for AO November 2006 November 2006 Camera head (Grenoble) Controller (Marseille) SPHERE XAO VLT Will be used on every 2nd generation AO instruments in Europe ! JRA1 FP6 First light: 2011 e2v 240x240 L3CCD September 2006 2007 Peltier cooled package Fast detectors

3. What are now the needs for ELT WFS detectors ? Fast detectors

4. Spot Elongation aperture 12m away elongation of 3” Rayleigh Backscatter 3 m Laser Launch Site 10 m 6” 40 m 2.5” .75” LGS based AO challenges on ELT Worse with Telescope Size Probably need ~ 20x20 pixels for each spot to properly sample the elongation. LGS image Courtesy KECK • Large amount of pixels for spot elongation issue • With pulsed laser: electronic shutter (sodium spot only) Fast detectors

5. Limitations imposed by actuator density: • Need High SR (>90% at 1.6 m) •  15-20 cm sub-aperture size •  2002 - 2562 actuators (42/0.2) for a 42-m telescope • WFS baseline solution: Pyramid with 4 detectors • Limitations imposed by Temporal Delay: • Halo  at small  (temp. part  5/3 ) • Halo temp. part (1 / Frame rate)2 From 1 KHz to 3.2 KHz  Planet detected 10x faster!(when temporal errors dominate) Pyramid requires less pixels than SH: 4 pix. / sub-ap. but split on 4 detectors, i.e. 1 pix/ sub-ap = 2562 pixels for each detector Contribution to halo due to temporal delay • Limitations imposedby Atm.Chromatic effects • Halo  at small  (chrom. part  5/3, 11/3) • When  = (obs-wfs)  thenHalo intensity  WFS from R to I band  Planet detected 7x faster!(when chromatic errors dominate) Contribution to halo due to chromatic effects obs=1.6 m E-ELT XAO WFS CCDs Requirements Exoplanets detection on E-ELT, requirements: • Higher contrast (up to C=109)(SPHERE: 107) • Smaller angular distance (as close as =30 mas)(SPHERE: 100 mas) Integration time needed to detect Planet  Star Halo Intensity XAO CCDs requirements: • 2562 pixels • 3 KHz (goal 4 KHz) frame rate • High QE for  = 800 to 1000 nm • Low read noise: 1-2 electrons/frame Fast detectors

6. Preparation activities in the frame of FP6 • Funded by ESO (FP6 ELT design study): • 2 feasibility studies for LGS AO detector dedicated to ELT (6 months, 50 k€ each) and one prototype (~1 year: 2007, 200 k€) • XAO best effort prototype based on PN Sensor technology: 2562 pixels, one amplifier per column, 200 k€, testing included • At the end, 2 types of AO detectors for ELTs are required: LGS and XAO Fast detectors

7. Image Store Serial Register Analog Front End A possible solution for LGS WFS detector ? 20 pixels (courtesy Roger Smith, Caltech) 20 pixels Programmable Centroiding Logic Array Simple Sequencer Clocks & Biases Centroid X,Y positions, intensity Master clock Power supply Programming interface x100 • 100x100 rectangular array of small CCDs. • Each CCD: 20x20 pixels • 700 Hz frame rate, ~ 1 e noise • Electronic shutter (for spot elongation) Fast detectors x100

8. 128:2-3 Mux. 128:2-3 Mux. R O I C 2-3 Outputs 9 Mp/s I I M M R O I C R O I C R O I C 2-3 Outputs 9 Mp/s 2-3 Outputs 9 Mp/s 2-3 Outputs 9 Mp/s M I I M 128:2-3 Mux. 256 Outputs 256 Outputs 128:2-3 Mux. 128 128 PN-CCD: a possible solution for XAO WFS on ELT ? • Interesting to evaluate now this technology for XAO • Propose a 200 k€ best effort contract with MPE/PN-sensors manpower • 256x256 split frame transfer PN-CCD device. • 512 outputs, uses four ROICs for goal frame rate of 3000 frames/sec at 1.5 e RON Fast detectors

9. Fast PN-CCD detector fabricated by MPE Main features: • detector size = 27×13.5 mm2 • 51 μm pixel size • 528×264 pixels in total, 264×264 in image area • split frame-transfer concept • image transfer time ≈ 30 μs • readout noise vs. frame rate: • 1.8 e- @ 10 .. 400 fps • 2.5 e- @ 400 .. 1200 fps • Next step: • 256x256 pixels • 3 kHz Frame rate • 1-2 e Noise • Good red response Fast detectors

10. Preliminary management structure Fast detectors

11. 2008 2010 2012 2009 2011 2013 Preliminary deliverables and schedule Detector definition and CFT Detector LGS dev Detector XAO dev LGS test camera XAO test camera LGS detector testing XAO detector testing Fast detectors

12. Eligible costs • XAO detector cost: 1 M€ • LGS detector cost: 2 M€ • Controller and camera head XAO: 200 k€ • Controller and camera head LGS: 200 k€ • Detector testing activity: 200 k€ • Total: 3.6 M€ • Requested to EC ? Fast detectors

13. Conclusion • JRA2 FP6: was dedicated to 2nd generation of AO instrument for 8-10 m class telescopes • FP7: two needs for E-ELT AO WFS detectors identified: • LGS WFS detector: very large pixel format to sample spot elongation, high frame rate (700 Hz), low noise (~1 e).TBC. • XAO WFS detector: for a pyramid WFS, 2562 pixels are sufficient, but extremely high frame rate (3 to 4 kHz) and very low noise (~1 e) are required. TBC. • ~ 5.5 years development (2008-2013) • 3.6 M€ eligible cost • For the proposed activity: at least ~ 3 European countries (Germany, Spain, France), 2 European institutions (ESO, IAC), ~ 3 laboratories (INSU/CNRS), 2 industrial partners . • AO applications are strategic for E-ELT but activity open to wider applications in the field of fast detectors. Fast detectors

14. Back Filled Epoxy Indium Bumps Bond Wire Array of small CCDs CMOS Sequencer, AFE AND Centroid Logic Array Package Package Pin LGS detector: could be Hybrid or Monolith • Monolith - cheaper but detector silicon determined by CMOS process; ok for LGS at 589nm. • Hybrid – expensive but detector can be optimized for good red response by use of high resistivity silicon. Fast detectors