Super-resolution Optical Imaging Using Microsphere Nanoscopy A thesis submitted to The University of Manchester For the degree of Doctor of Philosophy (PhD) in the Faculty of Engineering and Physical Sciences 2013 Seoungjun Lee School of Mechanical, Aerospace and Civil Engineering Super-resolution optical imaging using microsphere nanoscopy Table of Contents Table of Contents ...................................................................................................... 2 List of Figures and Tables ....................................................................................... 7 List of Publications ................................................................................................. 18 Abstract .................................................................................................................... 19 Declaration ............................................................................................................... 21 Copyright Statement ............................................................................................... 22 Acknowledgements ................................................................................................. 23 Dedication ............................................................................................................... 24 1 Introduction ...................................................................................................25 1.1 Research motivation and rationale ........................................................25 1.2 Aim and objectives ..................................................................................27 1.2.1 Aim ...................................................................................................27 1.2.2 Objectives ..........................................................................................27 1.3 Thesis outline ..........................................................................................28 2 Literature Review..........................................................................................31 2.1 Introduction ............................................................................................31 2.2 Microsphere optical nano-scopy .............................................................31 2.2.1 Fused silica microsphere in medium of air .........................................31 2.2.2 Fused silica microsphere in medium of ethanol ..................................36 2.2.3 Barium titanate glass microsphere in medium of isopropyl alcohol ....37 2.3 Superlens .................................................................................................39 2.3.1 Optical near-field superlens ...............................................................42 2.3.2 Optical far-field superlens ..................................................................43 2.3.3 Hyperlens ..........................................................................................46 2.4 Super-resolution cellular imaging microscopy ......................................50 2.4.1 Stimulated emission depletion (STED) microscopy ...........................51 2 Super-resolution optical imaging using microsphere nanoscopy 2.4.2 Photoswitchable imaging techniques (PALM and STORM) ...............54 2.4.3 Structured illumination microscopy (SIM) .........................................62 2.5 Photonic nanojets ....................................................................................65 2.5.1 Micro-cylinder photonic nanojets .......................................................66 2.5.2 Microsphere photonic nanojets ..........................................................70 2.5.3 Backscattering enhancement ..............................................................77 2.5.4 Experimental observation of photonic nanojet ....................................82 2.5.5 Experimental confirmation of backscattering enhancement ................87 2.6 Summary and identification of knowledge gap .....................................92 3 Methodology and Equipments ......................................................................93 3.1 Introduction ............................................................................................93 3.2 Materials .................................................................................................93 3.2.1 Microsphere .......................................................................................93 3.2.2 Blu-ray disc .......................................................................................94 3.3 Characterisation equipments .................................................................96 3.3.1 Scanning electron microscope (SEM) ................................................96 3.3.2 Optical microscope ............................................................................96 3.3.3 Sputtering machine ............................................................................97 3.4 Laser technology and devices .................................................................97 3.4.1 Nanosecond laser ...............................................................................97 3.5 Simulation tools.......................................................................................98 3.5.1 CST Microwave Studio......................................................................98 3.5.2 DSIMie simulation software ............................................................ 100 3.6 Experimental procedures ..................................................................... 101 3.6.1 Location of the microsphere ............................................................. 101 3.6.2 Light source of optical microscope .................................................. 101 3.6.3 Immersion liquid ............................................................................. 101 4 Effect of Surrounding Media on Microsphere Optical Imaging ............... 103 4.1 Introduction .......................................................................................... 104 4.2 Methods ................................................................................................. 106 3 Super-resolution optical imaging using microsphere nanoscopy 4.2.1 Limitation of optical resolution ........................................................ 106 4.2.2 Preparation of materials ................................................................... 106 4.2.3 Experimental setup .......................................................................... 107 4.3 Results and discussion .......................................................................... 107 4.3.1 Comparison of SEM and SMON images .......................................... 107 4.3.2 Magnification and image focal position in different media ............... 109 4.3.3 Specular highlight ............................................................................ 110 4.3.4 Mie theory with Poynting vector field .............................................. 112 4.4 Conclusions ........................................................................................... 114 5 Effect of Sphere Size on Optical Imaging ................................................... 115 5.1 Introduction .......................................................................................... 116 5.2 Theory and Experimental Procedure ................................................... 117 5.2.1 Theory of MONS technique ............................................................. 117 5.2.2 Experimental detail .......................................................................... 120 5.3 Results and discussion .......................................................................... 120 5.3.1 SEM image ...................................................................................... 120 5.3.2 Experimental observation of polystyrene microspheres .................... 122 5.3.3 Magnification and focal image position ........................................... 123 5.3.4 Mie theory with Poynting vector field .............................................. 128 5.4 Conclusions ........................................................................................... 131 6 Super-resolution of Imaging of Sub-surface Nano Structures .................. 132 6.1 Introduction .......................................................................................... 133 6.2 Methods ................................................................................................. 134 6.2.1 Preparation of materials ................................................................... 134 6.2.2 Experiment setup ............................................................................. 134 6.2.3 Simulation setup .............................................................................. 135 6.3 Results and discussion .......................................................................... 136 6.3.1 Observation of optical transparent super-resolution .......................... 136 6.3.2 Experimental calibration .................................................................. 139 6.3.3 Directional Poynting vector flow with electric intensity ................... 140 4 Super-resolution optical imaging using microsphere nanoscopy 6.3.4 FWHM and DMI ............................................................................. 142 6.4 Conclusions ........................................................................................... 143 7 Microsphere