| Random surface is the most common form of the surface physical system, from the smallmatter as molecules and atoms to the large matter as the Earth are random rough surface. Thestudies of the random surface in many scientific and technological fields, such as: dynamics ofthin film growth, microelectronic components processing, medical imaging and diagnosis, haveimportant significance, therefore, the characteristics of random surface is always a concernedissue in the research about random surface. When the light passing through the random surfacewith the reflection or refraction, the scattering intensity profile changed with the granularrandom modulation because of the random superposition of the scattered light composition, thescattering light field forms the speckle field. The characteristics of the speckle field is refer to thestatistical properties of the random surface, and it also has great significance to the lightdiffraction, scattering and optical vortex. By the detection and measurement of the speckle field,the speckle images can be obtained directly, which not only can be used to analyze the statisticalproperties of the speckle field, but also can calculate the surface parameters that are fordescribing the random surface.Surface plasmon polaritons (SPPs) are an electromagnetic excitation coupled with electronon dielectric-metal interface which propagates along the interface and decays exponentially inthe vertical direction. Surface plasmon polaritons is a kind of electromagnetic modes that isconfined in the near-field with the unique properties of breakthrough the diffraction limit andfield enhancement, and these all make the SPPs have many important applications in surfaceplasmon sensing, surface enhanced Raman scattering and nanolithography. Especially, SPPsprovides a means to manipulate the electromagnetic field propagation in the nano-scale, and thesize of the photonic devices and the integrated optical circuit will be greatly reduced by theintroduction of surface plasmon polaritons, so that it is far less than the current level. Surfaceplasmon polaritons is not only critical for physics, but also for the related fields of chemistry andbiology, which make it has been the research focus in the past two decades.Observing and recording the light field are the basis of the optical measurement, people areconstantly creating and improving new optical imaging device, from eye observation tophotographic negatives to the photoelectron-coupled device (CCD). Using CCD to record theimages and directly store them in computer has become the most commonly used optical devices. The detection aperture of CCD has the certain size, usually, it need to match with the lens andthe mobile platform. A flexible image recording device will increase the efficiency of theexperiment and help to obtain the better experiment results.The content of this paper is the study of the above three aspects:(1) deriving thequantitative relationship between the autocorrelation function of the speckle intensity in deepFresnel region and the high distribution of random surface, set up the speckle detection systembased on the scanning fiber probe and experimentally detect the speckle field in deep Fresnelregion, extracting three surface parameters that is roughly consist with the results of the atomicforce microscopy measurement;(2) propose that Inverse problem algorithm can be used todesign the surface plasmonic devices, designing the corresponding radius-varied circular-slitdevices for the predetermined SPPs field distribution, using Huygens-Fresnel theory to calculatesurface plasmon polaritons field;(3) designing and building a two-dimensional optical imageacquisition system based on the mobile platform for collecting the light field in a wide range, thereliability of the system is proved by the square hole diffraction experiment. The content of thispaper is composed of the following five chapters:Chapter1presents the significance of the contents of this paper, give out the description ofthe random surface and the physical meaning of the surface parameters; the statistical propertiesof the speckle field Kirchhoff approximation theory; the basic properties of excitation andpropagation of the surface plasmon polaritons.Chapter2derive the relational expression between the autocorrelation function of thespeckle field in the deep Fresnel diffraction region and the surface parameters of the randomsurface; introduce the speckle detection system based on the scanning fibre-optic probe and itsoperating principle; extracting three surface parameters from the detection results, the surfaceroughness w, the lateral correlation length ξ and roughness exponent α; introducing theresults of the atomic force microscopy analysis, and compared with the results of theexperimental measurements; discussing these results.Chapter3giving out the brief introduction of the inverse problem algorithm in phaseretrieval: Gerchberg-Saxton algorithm (G-S algorithm); the approximate relationship between thephase retrieval of a circular slit and the relative position of a point in center region of circular slit;designing the corresponding radius-varied circular-slit devices for the predetermined SPPs fielddistribution; using the Huygens-Fresnel theory to calculate the SPPs field excited by thedesigned slit; analyze and discussion of these results.Chapter4proposing a two-dimensional image acquisition system based on the CCD andmobile platform; achieving the automated control of the system using the C++programming language; proving the reliability of this system by the diffraction experiment of the square hole.Chapter5we give the summary of this paper and put forward the further goal. |
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