Adaptive Optics for ELTs

1. Adaptive Optics for ELTs Strategic Investment for the Future Stephen Strom, NOAO Claire Max, CfAO Jerry Nelson, CfAO Matt Mountain, Gemini

2. Presentation Outline • Why we are here • Key messages • Current status of AO • Recent AO results; new frontiers in AO • AO is essential for ELTs • The scientific promise of AO systems on ELTs • Current investments and world competition • The need for coordinated investment using a roadmap • A proof of concept: laser development • A national roadmap for AO technology development • Approximate schedule and funding • Recommendations for Implementing a Roadmap

3. Why we are here • Provide updates on recent AO developments • Seek endorsement of CAA for: • NSF strategic investments in AO for ELTs using a community-developed “AO roadmap” as a guide • A recommended process for planning and coordinating investments in adaptive optics • Context: • Builds on a key decadal survey recommendation: implement a major AO program to enable ELTs • Provides key components; systems in time for ELTs

4. Key Messages • AO is now delivering quantitative science results • Capable and robust AO systems are critical to enabling and fully exploiting investments in ELTs • Critical ELT systems and components are well beyond the state-of-the-art • Large and sustained investment is needed to ensure AO readiness for ELTs by early in the next decade • Investments must be guided by a strategic plan • AO community has developed a consensus roadmap • NSF funding for AO could serve as early federal investment in a public-private GSMT • aligned with AASC recommendation re GSMT

5. AO Workshop: Participants + Consensus NameAffiliation Roger Angel University of Arizona Todd Boroson National Optical Astronomy Observatory Jim Breckinridge National Science Foundation Rich Dekany Jet Propulsion Laboratory Mark Ealey Xinetics Corporation Brent Ellerbroek Gemini Observatory Bob Fugate United States Air Force Ed Kibblewhite University of Chicago Claire Max Lawrence Livermore National Laboratory Jerry Nelson University of California, Santa Cruz Scot Olivier Lawrence Livermore National Laboratory Andreas Quirrenbach University of California, San Diego Thomas Rimmele National Solar Observatory Mike Shao Jet Propulsion Laboratory Steve Strom National Optical Astronomy Observatory Laird Thompson University of Illinois Allan Wirth Adaptive Optics Associates, Inc. Peter Wizinowich W. H. Keck Observatory Support Coordinated Strategic Investments: Implement a Roadmap Process

6. Key Messages • Investing in AO and following a roadmap will: • Create much needed sustained investment in key AO components and systems • Enable ELTs to operate successfully • Achieve full benefits of ELT investments • Enhance performance of existing telescopes

7. AO: Current Status • AO systems to date demonstrate its potential to: • deliver high fidelity, diffraction-limited images • enable large gains in sensitivity • improve photometric accuracy in crowded fields • reduce the size of instruments • Science enabled by AO is impressive • Measuring proper motions in the Galactic Center • Imaging accretion disks; precessing jets in YSOs • Resolving dense galactic and globular clusters • Measuring stellar fluxes; colors in nearby galaxies • Imaging planets and their satellites at high resolution

8. AO: Current Status However……… • Only a small percentage of the sky is accessible to current AO systems: laser guide stars needed • Laser systems are still very expensive, based on immature technology, and not robust • Detectors and DMs still limit performance • Wavefront sensing approaches not yet optimized • Data reduction techniques still under development • AO correction still limited to small FOVs But there has been substantial progress

9. Recent Results: Quantitative Photometry • AO performance can be well modeled • Predictions of image quality from models of atmospheric turbulence + optics confirmed • AO PSF fitting tools work well • Photometric errors in crowded fields ~2% • NICMOS vs AO photometry compares well

10. Galactic Center Region – 40”x40” composite AO corrected H & K Recent Results: Quantitative Photometry

11. Recent Results: Quantitative Photometry

12. 1” Recent Results: Black Hole at the Center of the Milky Way:Narrow-Field AO AO-on No AO

13. Multiple observations enable proper motion measurements. Symbol size ~ m Velocity dispersion vs radius yields black-hole mass Recent Results:The Black Hole at the Center of the Milky Way: Narrow Field AO

14. 2 merging disk galaxies Recent Results:Dual Black Holes at the Core of NGC 6240 WFPC2

15. Recent Results:Dual Black Holes at the Core of NGC 6240 Chandra high energy xrays Keck AO K band NICMOS J-H-K

16. The Next Frontier: Wide Field Imaging with Adaptive Optics Using MCAO Ragazzoni et al, 2000: • Collected optical data on a constellation of 4 stars • Used outer 3 stars to predict phase errors for the central star • Atmospheric phase error estimates superior to classical AO • MCAO will work!

17. Multiple laser guide stars Deformable mirrors conjugate to each turbulent layer, for larger field of view Multiconjugate AO One laser guide star Unsampled turbulence Primary mirrors

18. MCAO 1/2FoV 1/2 FoV AO 0 10 20 30 40 50 60 [arcsec] 40” 20” 40” a MCAO Can Provide Major Gains in FOV • Predicted performance of MCAO vs CAO: • Field of view area gain: J: 20-80 x, K: 10-20 x, depending on conditions • Photometric performance: accuracy proportional to Strehl variations over the field • MCAO should deliver 0.5% accuracy over 1-2’ FOV, or more than 10x CAO Enabling MCAO will require major investments

19. AO is Essential for ELTs • AO (at least low order) may be required to compensate for the effects of wind-buffeting • Capable AO systems are essential for reaping full value from investments in ELTs • Gains in point source sensitivity ~ D4 for diffraction-limited resolution in background-dominated images • Cost of an ELT ~ D2 • Benefit/cost ratio ~ D2 if AO can deliver high Strehl images, ultimately over substantial fields of view (MCAO) • Instrument size is prohibitively large absent AO • Science benefits are dramatic. For example: • Finding and characterizing planets • Characterizing component stellar pops in galaxies • Determining properties of forming galaxies

20. 20” M 32 (Gemini/Hokupaa) GSMT with MCAO NGST ELT AO Science: Stellar Populations

21. ELT AO Science : Galaxy Evolution Courtesy of M. Bolte

22. Current Investments in AO for ELTs • CfAO + NIO + Gemini (US share) + CELT + CAAO + UCSC-LAO: ~ $6M/yr • Key activities for existing groups: • CfAO: design studies; simulations; modest Na laser development • NIO: site characteristics; system studies; simulations • Gemini: MCAO science demonstrator, algorithms, Na Laser development • CELT: site characteristics; system studies; simulations • CAAO: deformable secondaries; Rayleigh laser beacons • LAO: testing of subscale prototypes & AO components • Bottom line: • These investments (private; state; federal; international) provide support for first steps toward ELT-capable AO • Key component developments need significant support

23. Current Investments: Europe • ESO –VLT will field first MCAO demonstratorlate 2003 (already through CDR) • In 2004 VLT MCAO program will explore alternative approaches, e.g. • layer-oriented vs. tomographic techniques • European network (OPTICON) established to coordinate and enhance European institutions AO modeling and simulation capabilities • funding post-docs at between 10-15 FTE’s/year • ESO now funding at least two parallel Na laser technology studies (e.g. fiber lasers) • 100m OWL is a highly effective coordinating force behind European AO efforts Our European colleagues are moving ahead aggressively

24. The need for NSF-supported Strategic Investment in AO for ELTs • Providing AO systems for ELTs will require a sustained, coordinated effort • Low order adaptive secondaries • High performance, narrow-field AO • High Strehl, wide-field AO (via MCAO) • Funding & timescales must be matched to the challenges • A successful example of a coordinated, strategic approach is already in hand: development of Na laser guide stars

25. AO off LGS AO The Potential of Na Laser Guide Stars ALFA AO System (Calar Alto): Na laser produced images with S ~ 0.2, within a factor of 2 of prediction And now Lick is producing S ~ 0.7, with the potential of (nearly) all-sky imaging

26. Lincoln Labs Solid State Laser Keck dye laser Today’s Na lasers are not yet robust

27. Solid-state sum-frequency lasers Air Force system Gemini laser project Fiber lasers ESO Raman laser LLNL-ESO-CfAO sum-frequency laser New laser approaches are promising but not yet mature

28. Meeting the Challenge: Defining a long-term laser development program • The AO roadmap effort highlighted the lack of a robust Na laser technology as critical to further AO development • However, the non-recurring costs of developing viable, lasers for Gemini, Keck and others was beyond the resources of any of the major adaptive optics programs • A focused, community-wide effort (Gemini, CfAO, Keck, USAF) was needed to develop “turn-key” affordable Na lasers for all ground-based telescopes

29. First Test of a Roadmap Approach • Gemini+CfAO+Keck+USAF (SOR) identified common system and component requirements • AURA, NSF and USAF worked together to identify funding to support a laser commercialization effort • used LIGO approach as a model • goal is to enable a committed private sector company to develop a product line • Results to date: • $5.2M already raised (further $4.3M requested from NSF) • Contract almost in place for first “commercial” 10W Na Laser • first step toward a fully-engineered, robust laser • additional funding may be needed to develop a product line • First successful tests at SOR of “diode” 10W prototype for engineering 50W demonstrator

30. What New Investments are Needed? • ELT studies identify as critical needs: • Deformable mirrors: thousands of actuators, large stroke; sizes ranging from 20-200 cm • Lasers (started but not completed): ~ 20-50W Na lasers (fully engineered to be robust and reliable) • 5-10 needed for ELTs; other systems • CCDs: large format, fast readout, low noise for wavefront sensing (512x512; ~kHz readout rates; 2e- read noise) • IR detectors: fast readout, low-noise for tip-tilt & focus sensors • The requirements for each component well exceed the current state-of-the art • Costs to develop needed components far exceed current investment levels Sustained investment over 5-10 years is critical

31. Implementing an AO Roadmap • Build on June 2000 AO Roadmap report • consensus of CfAO + AURA-NIO workshop • broadly-based, fully representative group • collaborative Na Laser program the first experiment • Take into account the rapidly accelerating international efforts to develop AO systems • Most cited AO science papers come from CFHT and ESO not from US telescopes (Crabtree 2002) • SPIE 2002 meeting provided clear evidence of impressive investment by the international community • Our colleagues in Europe are now developing highly capable systems for use with the VLT • Both MCAO and “Extreme AO” systems

32. Part II • Outline of national roadmap for ELT AO technology development • Key technologies, impacts • Schedule with milestones • Approximate funding level required • Recommendations for proposed roadmap process • Desired outcomes of this discussion

33. Key Technologies: Laser guide stars • Proposed Investment: • Na:develop fully-engineered, robust and affordable lasers • Rayleigh beacons:study and support integration into one or more demonstration systems relevant to ELTs • Expected Return: • Wider-field correction through use of MCAO on ELTs • Availability for multiple applications on existing telescopes (full sky coverage) • Extending AO corrections to shorter wavelengths (e.g. visible light on existing telescopes)

34. 03 04 05 06 07 08 09 10 • Na laser development • Fund NSF’s share of current collaboration with Air Force, Gemini • Fully engineered ~50 W solid-state lasers (already underway) • Advanced concepts (e.g. fiber lasers) • Commercialization • Fund commercialization of several promising approaches (LIGO laser as a model) • Goal: to create competition of at least two committed private sector companies to develop product lines • Rayleigh laser development • Study ELT concepts • Integrate into ELT plans if initial results are favorable (Arizona; Durham) Schedule of Key Activities: Lasers

35. Key Technologies: Deformable Mirrors • Proposed Investment: • Prototype and test wavefront correction elements with thousands of degrees of freedom; high stroke • MEMs • Adaptive secondaries • Thin face sheet DMs: extrapolate current technology to more actuators; lower cost • Expected Return: • Enable ELTs that deliver full AO potential • Lower cost/degree of freedom for existing telescopes • Provide higher Strehl at shorter wavelengths

36. 03 04 05 06 07 08 09 10 Requirements • Subscale prototypes • Construct, compare on modest scale • Full scale prototypes • Construct and test ELT-scale prototypes of most promising technologies Schedule of Key Activities: Deformable mirrors

37. Two deformable mirrors with 1000 actuators Xinetics, ~12” clear aperture MEMS ~ 1 cm

38. Key Technologies: Wavefront Sensing-1 • Proposed Investment: • Faster, lower noise detectors • Visible light: CCDs for wavefront sensing (need more pixels) • IR: arrays for tip-tilt, focus, ... sensing • Expected Return: • Enables wavefront sensing for ELTs • Provides greater sky coverage for existing telescopes • Enable use of fainter natural guide stars, less powerful lasers

39. Key Technologies: Wavefront Sensing-2 • Proposed Investment: • Develop alternative wavefront sensing techniques (today all AO systems use either Shack-Hartmann or curvature) • Direct phase measurements • Pyramid sensing • Compare performance, optimize for different astronomical AO goals • Expected Return: • Use available photons more efficiently for specific applications

40. 03 04 05 06 07 08 09 10 Requirements • Foundary runs • Evaluate performance • Coordinate with DoD Select most promising technology • Full scale prototypes • Production runs for 5122 detectors (visible) and very low-noise IR arrays Schedule of Key Activities: Detectors

41. 03 04 05 06 07 08 09 10 Analysis and simulation • Test concepts in lab • Compare for differing applications • What are fundamental performance limits of Shack-Hartmann, pyramid sensing, direct phase measurement Optimize for specific applications Schedule of Key Activities: Wavefront sensing concepts

42. Key Technologies: End-to-end Comparison of Competing Systems Concepts • Proposed Investment: • Evaluate and compare competing systems approaches • e.g., end-to-end comparison of layer-oriented vs tomographic approaches for 30m telescopes • benefits of multi-conjugate AO vs ground-layer compensation for selected science programs • Expected Return: • Choice of optimum architecture for ELTs • Improved performance on existing telescopes Realizing the full capabilities of a diffraction limited 30 m telescope is a technological challenge. But it is achievable with sustained investment.

43. 03 04 05 06 07 08 09 10 • Analysis and simulation • End-to-end simulations of competing approaches • Tomographic vs. layer-oriented • Ground-layer AO vs. MCAO • Test and compare concepts • Lab: full-up systems (degrees of freedom) but subscale dimensions, timescales • On existing telescopes: fewer degrees of freedom, but larger dimensions, real atmosphere Schedule of Key Activities: ELT AO concepts

44. Outcomes: At least two types of AO Systems Examples: • 2010-2012: Fund construction of high performance, narrow-field AO system for ELT application • 2010-2014: Fund construction of a capable MCAO system for ELT application • In both cases, these developments represent the culmination of the roadmap investments: • Integration of challenging & complex components into enabling systems for ELTs Essential, identifiable NSF investment in ELTs. Will benefit AO for all existing telescopes.

45. Funding Estimates: Historical Background • Bahcall report recommended $40M for the 1990s • Total public, private, international support exceeded this • Multiple approaches were funded • Appropriate to early R & D effort • Multiple successful approaches have now been implemented on current telescopes • Funding was far less successful in producing robust systems or key new components • some installations had small user base • duplication of effort • little strategic coordination of investments • For ELTs we need a better coordinated strategy to enhance the efficacy of investments, assure that ELT technology requirements can be met

46. Funding Estimates: Next Decade • Supporting enabling technology for ELTs will require investing at least $50M (AASC decadal report) • Integrating these components into capable 30m ELT AO systems will cost between $75M and $150M • NIO and CELT design studies • Numbers indicate the scale of needed investment • More detailed estimates will be developed in the next phase of the roadmap process US investment must approach $10 M / yr Requires increase over current levels of ~ $5 M / yr

47. A Community-based Roadmap Process • Community involvement; consensus is crucial • NOAO represents logical focus for engaging the community and developing needed consensus • In analogy with the TSIP program, NOAO would convene periodic meetings of a broad-based AO steering group in order to: • seek community feedback on the roadmap • work with NSF to set up process to evaluate proposals • evaluate achieved progress against roadmap goals • As with TSIP, funding could flow through NOAO • NOAO would not compete for AO funds

48. A Community-based Roadmap Process • An AO steering group would • Review advances in AO; supporting technologies • Review the overall pattern of federal investment • Assess the need for roadmap changes, and modify roadmap as needed • Recommend to NSF, and outline ‘announcements of opportunity’ to encourage proposals in key areas • Steering group meetings timed to influence NSF budget priorities; announcements of opportunity • This process is analogous to that used by the nuclear science community through NSAC

49. A Community-based Roadmap Process • In parallel, the NSF would • Actively seek proposals aligned with the roadmap • Focus funding on strategically important areas • Review proposals using a broadly-based panel • Astronomers; government lab scientists; industrial engineers and scientists • Panelists would have AO & systems experience • Provide sustained, long-term funding • Complex component and technology development require sustained investments for > 5 years • TSIP provides a model for planning and funding • AO funds for ELTs should be held in a ‘separate pot’ • Implementation of AO systems on current telescopes would come from other programs, not AO-ELT funds

50. Desired Outcomes of this Discussion • CAA support and recommendation for: • Focused and sustained investment in AO for ELTs • additional ~ $5M / yr of new funding is needed • A roadmap-based process to guide such investmentas described above. Success of AO on 30-m telescopes will require sustained investment for a decade. The time to start is now.