Opportunities for imaging with coherence Keith A Nugent

Opportunities for imaging with coherence Keith A. Nugent ARC Centre of Excellence for Coherent X-ray Science & School of Physics The University of Melbourne Australia Coherent X-ray Diffraction Workshop, BNL, May 14 2008

Outline of Talk • What can we aim for in 2013? • Introduction to CDI – brief • Fresnel CDI (FCDI) – Quantitative phase measurement – Application to malaria-infected red blood cell • Keyhole FCDI – imaging extended objects – Application to technology problem – Early 3 D results • Conclusions Coherent X-ray Diffraction Workshop, BNL, May 14 2008

Approaches to Coherent Imaging To Image extended objects in three-dimensions with 5 nm resolution • Holography – Recent work at BESSY – Limited path to high resolution • Phase-contrast – Very extensively used – Low resolution • Ptychography – SLS – Oliver Bunk – Extended objects, high resolution? • CDI – Plane wave incident • Isolated objects – Curved incident wave Coherent X-ray Diffraction Workshop, BNL, May 14 2008

Coherent imaging methods are being developed. Coherent Field Impose Measure Intensity, Keep Phase z Impose “support” Guess Phase Coherent X-ray Diffraction Workshop, BNL, May 14 2008

Coherent X-ray Diffraction Workshop, BNL, May 14 2008

Use prior knowledge of the incident wave to recover the “exit surface wave” leaving the object Coherent X-ray Diffraction Workshop, BNL, May 14 2008

The World’s Easiest CDI Experiment Fourier Fresnel Fourier Coherent X-ray Diffraction Workshop, BNL, May 14 2008

Reconstruction of the Illuminating Field HM Quiney, AG Peele, Z Cai, D Paterson, KA Nugent, Nature Physics, 2, 101 -104 (2006) Coherent X-ray Diffraction Workshop, BNL, May 14 2008

X-Ray CDI Coherent X-ray Diffraction Workshop, BNL, May 14 2008

Fresnel diffraction imaging GJ Williams, HM Quiney, BB Dahl, CQ Tran, KA Nugent, AG Peele, D Paterson, M de Jonge, Physical Review Letters, 97, 025506 (2006) Coherent X-ray Diffraction Workshop, BNL, May 14 2008

Quantitative Phase Measurement Average AFM height and reconstructed thickness for the four areas indicated in Fig 2(c). Region 1 2 3 4 AFM (nm) 370 ± 8* 344 ± 7 308 ± 15 348 ± 12 FCDI (nm) 360 ± 29 377 ± 28 297 ± 32 321 ± 19 Use prior knowledge of the incident wave to recover the “exit surface wave” leaving the object *Errors are estimated from the variance in the heights recovered within each region, as this includes intrinsic height variation the errors are therefore conservative. Clark, J. N. , et al. , Quantitative phase measurement in coherent diffraction imaging. Optics Express, 2008. 16(5) 3342 -3348. Coherent X-ray Diffraction Workshop, BNL, May 14 2008

What do we mean by “support”? Support is interpreted slightly differently here –the structure to be reconstructed is the coherent exit wave, including the illumination, not the scattering object itself. Coherent X-ray Diffraction Workshop, BNL, May 14 2008

Optical Demonstration CCD Camera Diode Laser Beam Optical Test Chart Coherent X-ray Diffraction Workshop, BNL, May 14 2008

Coherent X-ray Diffraction Workshop, BNL, May 14 2008

Independent Fresnel CDI images of a large object Experimental data obtained using coherent visible light Coherent X-ray Diffraction Workshop, BNL, May 14 2008

X-Ray CDI Coherent X-ray Diffraction Workshop, BNL, May 14 2008

Coherent X-ray Diffraction Workshop, BNL, May 14 2008

Coherent X-ray Diffraction Workshop, BNL, May 14 2008

Have achieved a resolution of ~15 nm! B Abbey et al, “Keyhole Coherent Diffractive Imaging”, Nature Physics, Published on the web March 9, 2008 Coherent X-ray Diffraction Workshop, BNL, May 14 2008

Exceeds resolution of STXM with same optics, by a factor of ~4! Coherent X-ray Diffraction Workshop, BNL, May 14 2008

Images of a fuse-bay sample Coherent X-ray Diffraction Workshop, BNL, May 14 2008

All of the conceptual and methodological pieces are in place for us to achieve 3 D imaging of extended objects with 5 nm spatial resolution Coherent X-ray Diffraction Workshop, BNL, May 14 2008

Collaborators • • • David Paterson Harry Quiney (UM) (Australian Synchrotron) Andrew Peele (La Trobe) • Martin de Jonge (APS – Garth Williams (UM) Now AS) Lachlan Whitehead (UM) • Brian Abbey (UM) • Ian Mc. Nulty (APS) • Jesse Clark (La Trobe) • Z Cai (APS) • Leann Tilley (La Trobe) • Eric Hanssen (La Trobe) Coherent X-ray Diffraction Workshop, BNL, May 14 2008