Super-resolution optical microscopy based on photonic crystal materials Mickaël Guillaumée

Introduction: Optical Microscopy and Diffraction Limit Resolution limit of an imaging system: High NA : immersion objectives Limit: small range of transparent materials with high n Near Field Optical Microscopy: collection of evanescent waves (high k//) in close proximity to the studied sample Really high resolution but very slow and not convenient => Necessity to find a Far-field technique for nanometre scale resolution microscopy PO-014 | M. Guillaumée | Page 1

Imaging through Photonic Crystal Space Principle: Test object Fourier Transform (FT) k space collected by the objective PO-014 | M. Guillaumée | Page 2

Imaging through Photonic Crystal Space Principle: Test object Fourier Transform (FT) Inverse FT of the area inside the circle k space collected by the objective PO-014 | M. Guillaumée | Page 3

Imaging through Photonic Crystal Space Principle: Test object Fourier Transform (FT) K k spaces with integer number of K are equivalent N. Le Thomas, R. Houdré et al. Grating-assisted superresolution of slow waves in Fourier space, Physical Review B, 76, 035103 2007 PO-014 | M. Guillaumée | Page 4

Imaging through Photonic Crystal Space Principle: Inverse FT of the area inside the circles Test object Fourier Transform (FT) K k spaces with integer number of K are equivalent PO-014 | M. Guillaumée | Page 5

Imaging through Photonic Crystal Space When spatial filtering with photonic crystal can be considered valid? Bloch wave: Necessity to get constant to get high spatial frequencies: => Achieved for high modulation of RIX First Brillouin zone wave vector Inverse lattice wave vectors B. Lombardet, L. A. Dunbar, R. Ferrini, and R. Houdré. Fourier analysis of Bloch wave propagation in photonic crystals, J. Opt. Soc. Am. B, 22, 1179, 2005 PO-014 | M. Guillaumée | Page 6

From theory to experiment… Need for far field imaging: transfer high spatial frequency in free space => Image magnification above the diffraction limit should be produced by the photonic crystal based microscope Curved photonic crystal boundary as a magnifying lens: => Challenging because refraction highly dependent on frequency and propagation direction Solution: reflecting optics => Curvature of the boundary in order to get a magnified image PO-014 | M. Guillaumée | Page 7

Experimental procedure: surface polaritonic crystal 2D photonic crystal material replaced by surface polaritonic crystal: Surface Plasmon Polariton (SPP) wave surface wave propagating at an interface metal/dielectric PO-014 | M. Guillaumée | Page 8

Experimental procedure: surface polaritonic crystal 2D photonic crystal material replaced by surface polaritonic crystal: Surface Plasmon Polariton (SPP) wave surface wave propagating at an interface metal/dielectric Excitation by a periodic structure : K C. Genet and T. W. Ebbesen. Light in tiny holes, Nature 445, 39, 2007 PO-014 | M. Guillaumée | Page 9

Photonic crystal and SPP: historical information Full photonic Band Gap observed for the first time in the visible with SPP Kitsen, Barnes and Sambles. Full Photonic Band Gap for Surface Modes in the Visible, Physical Review Letters, 77, 2670, 1996 PO-014 | M. Guillaumée | Page 10

Experimental procedure PO-014 | M. Guillaumée | Page 11

Experimental procedure Propagation of “SPP Bloch waves” with right excitation condition Reflection on a glycerin droplet boundary acting as an efficient magnifying mirror (high neff) Image formation at the exit of the “SPP crystal lens” (after the nanohole array) Scattering of light into free space due to surface roughness (higher in the image formation area) Collection with a regular microscope PO-014 | M. Guillaumée | Page 12

100nm hole diameter, 40nm distance between hole edges, 500nm period Experimental results High resolution but distortion of the image (image magnification depend on the object position with respect to the mirror 100nm hole diameter, 40nm distance between hole edges, 500nm period PO-014 | M. Guillaumée | Page 13

Experimental results: biological application T4 phage virus: 200nm long, 80nm wide T4 phage virus PO-014 | M. Guillaumée | Page 14

Conclusion Interesting scientific concept Technique has to be improved: Image distortion in that configuration Control of the mirror No theoretical prediction of the microscope resolution PO-014 | M. Guillaumée | Page 15

Thank you for your attention.