Jeremy Allington-Smith AstroPhotonica Europa coordinator Centre for Advanced Instrumentation Durham University

1. NE Approaching end of jet Part of Disk Nucleus Receding SW end of jet Opticon Board Meeting 10-11 Nov 2008, Porto Astrophotonics promise This talk focusses on PROMISE not PROGRAMMATICS Jeremy Allington-Smith AstroPhotonica Europa coordinator Centre for Advanced Instrumentation Durham University

2. Acknowledgements Pierre Kern*(LAOGrenoble) Joss Bland-Hawthorn*(U. Sydney; AAO) Martin Roth*(AIP) Robert Thomson (Heriot Watt U) Tim Birks(U. Bath) Jason Corbett(CfAI, Durham U+) ... and their associates ... and all our partners inAstroPhotonica Europa (includes Porto, ESO, MPIA…..) * Opticon-FP7 co-investigators, + now at Malvern Instruments

3. What is it? Astrophotonics= Astronomy + Photonics The application of photonic principles and devices to astronomy Astrophotonica Europa=a European partnership to achieve this goal

4. Why we need it • Main themes for astronomy • Equation of state of the universe • Galactic archaelogy • Extrasolar planets; AGN studies → large aperture and high spatial resolution → ELTs → very high spatial resolution → LBOIRI AstroPhotonics can bring major benefits to: • Highly-multiplexed spectroscopy – a critical technique - • Specific technical problems for ELTs to be solved • Improved utility of long-baseline opt/IR interferometry • Pre-dispersion removal of telluric background

5. What actually is photonics? L The behaviour of a medium depends not only on the type of its constituent atoms but also on the geometrical layout of the atomic oscillators • Examples: • Photonic crystal fibres (1-D) • Slab waveguides (2-D; VPHg a very simple example) • Waveguide arrays (3-D)

6. Photonics in 1D: PCFs Photonic band-gap Index guidance Reflection of light from medium of index lower than that of the cladding Reflection of light from medium of index higher than that of cladding

7. Applications PCF capabilities Long-baseline interferometry OH suppression Highly-multiplexed spectroscopy Miniaturisation for ELTs

8. New fibre technology • Extended wavelength range for PCFs: • Endlessly single mode (interferometry) • New materials and construction for e.g. infrared • Fibres designed for multiplexing • Multicore + “nano-lens” arrays = micro IFUs • Telluric background rejection • Suppression of airglow forest • Etendue conservation via single modes ? • No Focal ratio degradation • Large coupling interface (mode area; LMA) ~10 recent papers by AAO & Durham

9. Interferometry (long-baseline opt/IR) Brief summary - interface with interferometry and fast detectors activities in OPTICON • Long heritage in interferometry: FLUOR, OHANA, IONIC • Specific photonic solutions for critical functions: • beam combination • light transport (PCF junctions/switches) • Integrated Optics to simplify complexity of multilayer systems via e.g…. • On-chip integration - e.g. novel fringe tracker via Lipmann interfometrySingle photon detectors (Grenoble Quantum Dots (St Andrews, ATC)

10. OH suppression Bland-Hawthorn et al. (2004)*; Leon-Saval et al, (2005)** NIR airglow emission  artefacts & reduced SNR Extended wings due to disperser  Remove before dispersion Currently limited by number of modes coupled from telescope  = Numerical aperture d = fibre core diameter (40-100µm)  10 < M <100 *OpEx, 12, 5902 ** Opt. Lett. 30 2545

11. Datacube y  MOS x Multiplexed spectroscopy • Must dilutely sample field due to detector cost • Need arbitrary choice of spaxels contiguous or not • MOS+IFS = Diverse Field Spectroscopy

12. Observation control Telescope focus Selected regions Primary feed Switcher Spectrograph feed Recorded spectra Spectrographs Spectrograph slit Celestial Selector For DFS Murray & Allington-Smith (in prep) Allington-Smith, Murray & Padgett (in prep) • Integrated optics • Tiny replicated spectrometers • Novel fibres (PCFs)

13. Reduce volume by factor 50? R. Contentet al. (Durham) Miniaturising instruments? Fore-optics & pickoff mirrors • Gigantic integral field unit for ELT (GSMT) • 3'x3' @0.1" IFU • Beam size ~250mm • R = 2000 Dimensions: 6 x 7 x 8m Thomson, Kar & Allington-Smith (2008)

14. One miniature integrated photonic spectrograph per fibre Integrated Photonic spectrograph Integrated Photonic spectrograph Integrated Photonic spectrograph Integrated Photonic spectrograph Integrated Photonic spectrograph Data Multi-mono mode transition Multi-mono mode transition Multi-mono mode transition Multi-mono mode transition Multi-mono mode transition Arrayed Waveguide Grating Arrayed Waveguide Grating Arrayed Waveguide Grating Photonic Disperser (AWG,Lipmann) Arrayed Waveguide Grating Linear Detector array Linear Detector array Linear Detector array Linear Detector array Linear Detector array Multimode fibres Demonstrated but not in integrated device Devices exist but not integrated to detector Exists but not integrated in spectrograph Photonic spectrograph Telescope focus Massively multiplexed Sliced/IFU

15. Photonic disperser: AWG Arrayed Waveguide Gratings avoid geometrical limits of SL gratings using phased fibre arrays • Potential size advantage of 5-10 in linear size;  cost factor 30-1000!(Bland-Hawthorn et al., AAO)

16. Photonic disperser: “SWIFTS” LeCoarer et al. Nature Photonics 1, 473 (2007) • Detect evanescent field in waveguide • Detectors? • SSPD • Quantum dots

17. Enabling tchnology: ULI • OHS by multi-singlemode transitionsand photonic phased array dispersers need 3D waveguide networks • Thomson, Kar & Allington-Smith(OpEx submitted) propose Ultrafast laser inscription(Thomson et al. OpEx 15, 11691 (2007). • Highly focussed, steerable laser changes refractive index in suitable materials when power density exceeds a threshold near focus

18. ULI 3D waveguides • OHS: Replace complicated PCF transition with mass-producible units • Photonic disperser: maximise phase shift via spiral geometry

19. Organisation Exploit recent advances in Photonics by telecommunications industry Build on Europe’s innovation heritage (e.g IFS) Get together with your friends → AstroPhotonica Europapartnership

20. AstroPhotonica Europa A European research partnership Partnership UK/France/Germany/Netherlands/Spain/Portugal • Astronomy Institutes • Photonics institutes • Foundries (detailed design and prototyping) Funding • EU via OPTICON (FP7 support) • National and regional funding (e.g. InnoFspec, Potsdam) • In-kind contributions of effort and facilities Activities • Workshops & Networking • Research & assessment Synergies • Regional optics technology networks & Industry

21. AstroPhotonica Europa A European research partnership

22. AstroPhotonica Europa A European research partnership Further information Contact co-ordinator j.r.allington-smith@durham.ac.uk http://star-www.dur.ac.uk/~jra/astrophotonica.html

24. Conclusions • To understand the origins of the cosmos and of ourselves astronomers needs new technology • Exploitation of photonic principles and devices already developed will help us do this • Without it, instrumentation for the next generation of telescopes may run into major problems • Find out more!

25. The end