ARC 11/02/10 Recent Advances in Surface Plasmon Resonance: From Biosensor to Space/astronomical Interest Hololab and CSL S. Habraken, C. Lenaerts, and J. Hastanin

2 ARC (11/02/10) Surface Plasmon Resonance ? incident angle, θ Intensity E → Z I Dielectric Metal Evanescent wave θ SPR : Quantized oscillations of free electrons excited by an evanescent elm wave  Reflectivity loss

3 ARC (11/02/10) SPR excitation by coupling with elm wave How to produce the evanescent wave ? 1. ATR configuration (classical) 2. Grating based configuration (more recently) Metallic filmPrism Grating Metallic film

4 ARC (11/02/10) Linked project: Plasmobio (Hololab, CSL, Univ. Mons and Lille) –Interreg project on micro bio fluidic and new architectures of SPR sensors ( ) Gold layer m=1 θ SPR Blazed Metallic gratings Sample Substrate βmβm α n L =1,33 Towards Detector TM; λ=760 nm

5 ARC (11/02/10) Cantilever-based SPR Laser Gold Layer Cantilever Prism Metal Cantilever FDTD modelization: Electric Field E x Laser hνhν Cantilever bending induced by radiation absorption or adsorption of chemical species Bimorph cantilever with a semiconductor layer

6 ARC (11/02/10) Cantilever-based SPR Cantilever Réflect ivité Inicident angle Réflect ivité Gap thickness Gap Excitation efficiency is very sensitive to gap thickness variation (up to 2 nm resolution !) Possible Space Application: X-ray detector (  Anthony Hervé talk) Gas sensor (residual atmosphere on a planet)

7 ARC (11/02/10) SPR Spectroscopy Basic Principle: –Spectral scanning instead of angular scanning !  Frozen angle with polychromatic light beam Some advantages: –High degree of freedom: for a specific application, optical parameters of the layers can be determined independently and the highest resolution can be obtained –High degree of miniaturization of SPR sensor optical imaging system, especially when coupling and dispersing are combined in the same element (grating)

8 ARC (11/02/10) SPR based on Coupler and disperser Grating Thin metal film gratingThick metal film grating Principle: Coupling in +1order / Dispersing in -1order Grating with thin metal coating Diffraction order Substrate Liquid θ Diffraction order CCD θ Liquid Grating with thick metal coating Substrate Diffraction order Detection in reflective mode CCD Detection in transmitive mode

9 ARC (11/02/10) SPR based on Coupler and disperser Grating Simulation: based on the rigorous elm theory : integral method (PC-Grate) Typical results for thin metallic grating: with asymmetrical grating interfaces such as: Transmitive mode: Reflective mode: Efficiency of trans. order m=-1 Wavelength, nm n liquid =1,38 n liquid =1,33 δλ =35-40 nm Efficiency of reflect. order m=-1 Wavelength, nm δλ =30-35 nm n liquid =1,38 n liquid =1,33

10 ARC (11/02/10) Conclusions SPR offers an intrinsic very high sensitivity Biomedical applications are under development with rapid worldwide advances (science and technology) Space/astronomical applications are related to: 1.Detection of radiation or energetic particles (see RX detector array with Anthony) 2.Detection of low concentration of fluid, especially gas molecules adsorbed on a functionalized layer: very high resolution and sensitivity with a miniaturized spectrometer: to be demonstrated… Great opportunity for synergy between biophotonics and astro !

11 ARC (11/02/10) Annexe Wavelength, nm δλ =25-31 nm n liquid =1, n liquid =1,33 0,3 Efficiency of reflect. order m=-1