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Premium member Presentation Transcript Wave front shaping : Elbert van Putten Complex Photonic Systems Wave front shaping Controlling light in disordered materials Acknowledgements : Acknowledgements Duygu Akbulut Ivo Vellekoop Allard Mosk Ad Lagendijk Willem Vos Photon Scattering Group (AMOLF, Amsterdam) Complex Photonic Systems Light and Disorder : Light and Disorder Scattering obstructs view Scattering is a nasty problem : Scattering is a nasty problem target Today I’ll show you that scattering can be extremely useful Outline : Outline Scattering in optics Wave front shaping Focusing through opaque materials Focusing inside opaque materials Speckle : Speckle - Light still interferes after it is scattered - Transmitted light has random phase: laser speckle - Low intensity, no resolution. How to describe this scattering? : How to describe this scattering? See the sample as a waveguide… Channels in x = Channels out How to describe this scattering? : How to describe this scattering? …and add disorder to mix the channels Channels in x = Channels out Field at an outgoing channel : Field at an outgoing channel Outgoing channel Ingoing channels random, uncorrelated scattering coefficients =1 Controlling channels : Controlling channels What happens if we could control the incident channels… =1 Controlling channels : Controlling channels We choose the phase to maximize the amplitude of Eb =1 Controlling channels : Controlling channels We choose the phase to maximize the amplitude of Eb =1 Controlling channels : Controlling channels By controlling the incoming channels we control how light propagates! =1 Outline : Outline Scattering in optics Wave front shaping Focusing through opaque materials Focusing inside opaque materials Speckles : Speckles sample target total field in target Basic idea : Basic idea Digital feedback system sample target Divide incoming wavefront in N segments Basic idea : Basic idea sample phase modulator with N segments target total field in target Outline : Outline Scattering in optics Wave front shaping Focusing through opaque materials Focusing inside opaque materials Slide 19: LCD Experimental setup Spatial amplitude and phase modulation using commercial TN LCDsvan Putten, Vellekoop & Mosk,Appl. Opt. 47, 2076 (2008). Slide 20: LCD Sample: 10 µm layer of TiO2 pigment Light source: 633 nm HeNe laser Feedback: 1 pixel of CCD camera Experimental setup Focusing light through paint : Focusing light through paint Focus is more than 1000 times brighter than the background Vellekoop & Mosk. Opt. Lett. 32, 2309 (2007) Perfect focusing : Perfect focusing Vellekoop, Lagendijk & Mosk, Nat. Photon. 5, 320 (2010) Wave front shaping Diffraction limit of the sample Slide 23: Teeth (ex vivo) Paint Daisy petals Scotch tape Prepared chicken Egg shell Works on a variety of materials Outline : Outline Scattering in optics Wave front shaping Focusing through opaque materials Focusing inside opaque materials Focusing inside : Focusing inside Open problem in science, technology and biomedical imaging Highly relevant for near-field superresolution with metamaterials. Need feedback signal from inside Focusing inside : Focusing inside Use fluorescent probe particle (150 nm) forfeedback. Enhanced fluorescence : Enhanced fluorescence Size of the sphere (same scale) 20x more light! Plane wave illumination Shaped wave illumination Intensity vs. depth : Intensity vs. depth Conventional optics corrected for all aberrations (classical adaptive optics) Wave front shaping Vellekoop, van Putten, Lagendijk & Mosk, Opt. expr. (2008) Wave front shaping works independent of depth Size of the focus : Size of the focus Resolution illumination Size of the focus : Size of the focus Resolution illumination Wave front shaping Size of the focus : Size of the focus Resolution illumination Wave front shaping Resolution detection van Putten, Lagendijk & Mosk, submitted Conclusions : Conclusions Disorder no longer a nasty problem Light can be focused at any location in and outside a disordered material Wave front shaping is a powerful tool to control light propagation Slide 33: As discussed in Nature Physics 4, 91 (2008) Resolution and contrast : Resolution and contrast Normal lens: Wavefront error deteriorates focus size Opaque lens: Wavefront error scattered into background (deteriorates focus contrast) Graphical representation : Graphical representation contribution of segment 1 contribution of segment 2 contribution of segment N Maximize Eb Global maximum : Global maximum before after global maximum Finding the optimal wavefront : Finding the optimal wavefront Adjust phase of individual segments until contribution is in phase with total field Intensity of focus : Intensity of focus You do not have the permission to view this presentation. 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vPutten_ANP2010_orig inal aSGuest61001 Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 7 Category: Entertainment License: All Rights Reserved Like it (0) Dislike it (0) Added: August 15, 2010 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript Wave front shaping : Elbert van Putten Complex Photonic Systems Wave front shaping Controlling light in disordered materials Acknowledgements : Acknowledgements Duygu Akbulut Ivo Vellekoop Allard Mosk Ad Lagendijk Willem Vos Photon Scattering Group (AMOLF, Amsterdam) Complex Photonic Systems Light and Disorder : Light and Disorder Scattering obstructs view Scattering is a nasty problem : Scattering is a nasty problem target Today I’ll show you that scattering can be extremely useful Outline : Outline Scattering in optics Wave front shaping Focusing through opaque materials Focusing inside opaque materials Speckle : Speckle - Light still interferes after it is scattered - Transmitted light has random phase: laser speckle - Low intensity, no resolution. How to describe this scattering? : How to describe this scattering? See the sample as a waveguide… Channels in x = Channels out How to describe this scattering? : How to describe this scattering? …and add disorder to mix the channels Channels in x = Channels out Field at an outgoing channel : Field at an outgoing channel Outgoing channel Ingoing channels random, uncorrelated scattering coefficients =1 Controlling channels : Controlling channels What happens if we could control the incident channels… =1 Controlling channels : Controlling channels We choose the phase to maximize the amplitude of Eb =1 Controlling channels : Controlling channels We choose the phase to maximize the amplitude of Eb =1 Controlling channels : Controlling channels By controlling the incoming channels we control how light propagates! =1 Outline : Outline Scattering in optics Wave front shaping Focusing through opaque materials Focusing inside opaque materials Speckles : Speckles sample target total field in target Basic idea : Basic idea Digital feedback system sample target Divide incoming wavefront in N segments Basic idea : Basic idea sample phase modulator with N segments target total field in target Outline : Outline Scattering in optics Wave front shaping Focusing through opaque materials Focusing inside opaque materials Slide 19: LCD Experimental setup Spatial amplitude and phase modulation using commercial TN LCDsvan Putten, Vellekoop & Mosk,Appl. Opt. 47, 2076 (2008). Slide 20: LCD Sample: 10 µm layer of TiO2 pigment Light source: 633 nm HeNe laser Feedback: 1 pixel of CCD camera Experimental setup Focusing light through paint : Focusing light through paint Focus is more than 1000 times brighter than the background Vellekoop & Mosk. Opt. Lett. 32, 2309 (2007) Perfect focusing : Perfect focusing Vellekoop, Lagendijk & Mosk, Nat. Photon. 5, 320 (2010) Wave front shaping Diffraction limit of the sample Slide 23: Teeth (ex vivo) Paint Daisy petals Scotch tape Prepared chicken Egg shell Works on a variety of materials Outline : Outline Scattering in optics Wave front shaping Focusing through opaque materials Focusing inside opaque materials Focusing inside : Focusing inside Open problem in science, technology and biomedical imaging Highly relevant for near-field superresolution with metamaterials. Need feedback signal from inside Focusing inside : Focusing inside Use fluorescent probe particle (150 nm) forfeedback. Enhanced fluorescence : Enhanced fluorescence Size of the sphere (same scale) 20x more light! Plane wave illumination Shaped wave illumination Intensity vs. depth : Intensity vs. depth Conventional optics corrected for all aberrations (classical adaptive optics) Wave front shaping Vellekoop, van Putten, Lagendijk & Mosk, Opt. expr. (2008) Wave front shaping works independent of depth Size of the focus : Size of the focus Resolution illumination Size of the focus : Size of the focus Resolution illumination Wave front shaping Size of the focus : Size of the focus Resolution illumination Wave front shaping Resolution detection van Putten, Lagendijk & Mosk, submitted Conclusions : Conclusions Disorder no longer a nasty problem Light can be focused at any location in and outside a disordered material Wave front shaping is a powerful tool to control light propagation Slide 33: As discussed in Nature Physics 4, 91 (2008) Resolution and contrast : Resolution and contrast Normal lens: Wavefront error deteriorates focus size Opaque lens: Wavefront error scattered into background (deteriorates focus contrast) Graphical representation : Graphical representation contribution of segment 1 contribution of segment 2 contribution of segment N Maximize Eb Global maximum : Global maximum before after global maximum Finding the optimal wavefront : Finding the optimal wavefront Adjust phase of individual segments until contribution is in phase with total field Intensity of focus : Intensity of focus