Studies On The Characteristic Of The Speckle From Coherent To Incoherent Superposition

The random surfaces as important parts make up of nature,from atoms and molecules to large mountains and hills are rough random surfaces. It is very important to study it, as it is essential for many aspects, such as the dynamics of film's growth,rupture aroused by concussion of orb,the design of micro-electronics component and so on. So many people have paid much attention to studying about random surfaces for a long time. When appropriate coherent light reflected from the rough surface or through the medium of Random fluctuations of refractive index, they will form a random intensity distribution, we call it speckle. Studying the characteristics of the speckle through the random surface light source, it is also of great significance in research on the Quantum entanglement properties. So in recent years, the surface has also been a research topic of concern when the light passes through the properties of random speckle.Since the last century 80's, we found some new optical phenomena during the process of spontaneous parametric conversion producing the two-photon entangled state in the theoretical and experimental studies of the nonlinear crystal, such as the "ghost" imaging, "ghost" interference and sub-wavelength interference and so on. Recently a series of new results show that the "ghost" imaging, "ghost" interference and sub-wavelength interference can also be achieved by using the intensity correlation of the non-coherent heat light. This similarity triggered a Quantum entanglement and classical correlation debate.The content of this paper is the study of the interference characteristics for the partially coherent light. We conducted a large number of theoretical and experimental studies, and has made important progress. We also studied the various factors that affect the speckle pattern. The paper gives the scattering surface's impact to speckle pattern in theoretical analysis, and the scattering surface movement on the impact of speckle pattern, but these studies are preliminary, not a in-depth analysis. The content of this paper is composed of the following five chapters:Chapter 1 presents the significance of the contents of this paper, give the background and the recent developments of interference with partially coherent light, give a summary of random surfaces and its measurements, and introduce the application of the interference with partially coherent light in other areas.Chapter 2, gives a systematic introduction of optical speckle first-order statistical properties, and gives a research method of incoherent light and partially coherent speckle pattern intensity superposition in the theory. For the sum of incoherent light speckle pattern, firstly we analyses the summing of e two speckle patterns, and then apply to the case of sum of N speckle patterns. Chapter 3, describes our experimental design, sum the value of the speckle pattern in the experiment, and observes the phenomenon of the partially coherent light which is similar to the interference pattern of the double-slit the speckle with the intensity measurement method, and analyses theoretically the results with the sum theory of the intensity given earlier, which are consistent with the experimental results image. In our practical measurement process, the intensity measurement is simpler than the measurement of intensity correlation, and much easier to be operated.Chapter 4, makes further theoretical analysis for the obtained pattern in the experiment, calculate the contrast ration of the speckle pattern in statistical methods, and study the various factors that affect the speckle pattern. We analyses the impact of the transverse movement of the scattering surface for the speckle pattern from the obtained pattern. In this section, we only describe and analyze simply the results which are the interference of the particles and speckle particles through the double-slit, and there is no deeper analysis in this paper, this will be the focus of our future work.Chapter 5, we give the summary of this paper and put forward the further goal.