Dissertation > Excellent graduate degree dissertation topics show
A Study on Propagation Properties of Partially Coherent Beams
Author: WuYunMei
Tutor: WangXiQing
School: Southwest Jiaotong University
Course: Optical Engineering
Keywords: Partially coherent beam Transmission characteristics Complex Gaussian function Nonparaxial transmission
CLC: O438
Type: Master's thesis
Year: 2007
Downloads: 272
Quote: 3
Read: Download Dissertation
Abstract
In recent years, partially coherent beam caused great interest in the study, partially coherent light source can produce laserlike farfield intensity distribution, intensity uniformity is better than a fully coherent laser beam. But this part of the research has focused on the Gaussian  Schell model (GSM) beam, the beam intensity distribution and the complex degree of coherence are Gaussian distribution. This article describes the other two types of new partially coherent light model that partially coherent modified Bessel  Gauss beam (MBGB) and the first class of zeroorder Bessel  Schell model (JSM) beam study partially coherent optical transmission transform the basic theory and analysis methods. In practical applications, the transmission of the laser beam is often limited by the diaphragm, and therefore limited by apertures part of the coherent beam propagation characteristics MBGB and JSM research is necessary. However, when the beam has a larger angle of divergence or beam waist can be compared with the wavelength, the paraxial approximation is no longer valid. With the progress of the study of diode lasers, photonic crystals, microoptics and microcavity laser, partially coherent beam transmission in nonparaxial areas within has attracted extensive attention, partially coherent nonparaxial beam of MBGB and JSM characteristics has important theoretical significance and practical value. The research work in this paper include: 1. On a partially coherent MBGB and JSM beam through paraxial optical ABCD system transmission hard aperture, using the hardedged aperture function expansion method for a finite number of complex Gaussian functions and derive approximate analytical propagation equation. Freespace transmission, for example the partially coherent MBGB in the case of an Aperture numerical calculation, calculation error and the scope of analytical formulas obtained are discussed. The results show that the complex Gaussian function expansion method can be quickly studied analytically the partially coherent MBGB through the circular aperture free space transmission characteristics, analysis Fresnel number, the truncation parameter after the diaphragm of partially coherent MBGB after light intensity distribution impact. And JSM focusing properties of the beam through the circular aperture thin lens system are analyzed and discussed. The numerical results show that the relative focal shift, truncation parameter related with the Fresnel number. 2. Generalized Rayleigh diffraction integral formula and the theory of partially coherent light out the arbitrary order nonparaxial partially coherent MBGB and nonparaxial JSM beams in free space resolution transmission equation is derived. As a special case, given the nonparaxial partially coherent MBGB farfield formulas and paraxial part coherent MBGB transmission formula. Numerical calculation and analysis show that the f parameter of the partially coherent MBGB nonparaxial characteristics important; addition, the spectral degree of coherence parameter ξ also affect the beam nonparaxial behavior. Nonparaxial JSM beam nonparaxial JSM analytical propagation equations and the phase of the beam in the farfield and paraxial approximation analytical formulas. Research shows, f Parameters and f_β parameters on the JSM beam nonparaxial behavior f parameter influence the nonparaxial JSM beam of the phase distribution. 3. Under normal circumstances, the focal position of the focused light beam to define the axial intensity of the position of the maximum point. When the zero axis intensity axis intensity method loses its meaning, this time can be the ring circumference power law to discuss the focal plane of the beam position; Moreover, due to the nonplanar waveguide factors, the focus position of the focal plane position not necessarily coincide. The view from practical application and the energy concentration is more reasonable to define the actual focal plane, the plane of the beam waist position (minimum spot size plane). Cosine  Gaussian beam, for example, the actual focal plane and its position on the beam are analyzed and discussed. In cosine  Gaussian beam through a thin lens focusing system based on the field distribution function using secondorder moment defined export focus cosine  Gaussian beam spot function analytic expression thus obtained waist width and position, and then to analytical expression for the cosine  Gaussian beam relative focal shift. Parameters and beam parameters of the optical system of the actual focal plane position and made a numerical calculation.

Related Dissertations
 Raindrop characteristics and signal transmission of the laser,P412.22
 Research on Propagation Properties of an Optical Surface Plasmonic Waveguide with a Bowtie Air Core,TN252
 Propagation Properties of an Optical Surface Plasmonic Waveguide with a Butterfly Air Core,TN252
 Propagation Characteristic of Nonlinear Planar Waveguides,TN252
 Design and Study on the Torque Behaviors of Liquid Viscous Couplings,U463.2
 The Study on the Silicone Oil Clutch and the Essential Techniques of It,TH133.4
 Design of Drilling Fluid Continuous Wave Generator and Experiment Research of Signal Transmission Characteristic,TE927
 A Empirical Study on Correlation、Periodicity and Transmission Characteristics of International Security Markets,F831.51
 Study the transmission characteristics of the photonic crystal using the finite difference time domain ( FDTD ),O734
 1GHz based on DDS technology developed scalar network analyzer,TM935
 Optical Transmission Property of Two Dimensional Photonic Crystal,O734
 Study on Propagation Properties of SuperGaussian Pulse in Optical Fibers,TN929.11
 Microstructure fiber optics Numerical Simulation,TN253
 The Design and Experimental Research of a Nonlinear Vibration Isolator,TB535.1
 Study on the Partially Coherent Array Beams Propagating Through Atmospheric Turbulence,O436.1
 Research on the Vibrational Properties of the Periodic Pipe Base on PCs Theory,TB123
 LaB_6 optical properties of firstprinciples calculations and experimental study,O482.3
 Broadband wireless communications multiuser scheduling and diversity techniques,TN92
 Polarization multiplexed differential quadrature phase shift keying signal transmission characteristics,TN929.1
 Theoretical and Experimental Studies on Partially Coherent Beams,O436
CLC: > Mathematical sciences and chemical > Physics > Optics > Information Optics
© 2012 www.DissertationTopic.Net Mobile
