Dissertation > Excellent graduate degree dissertation topics show

Femtosecond laser and Si \u003csub\u003e 3 \u003c/ sub\u003e N \u003csub\u003e 4 \u003c/ sub\u003e crystal interaction theoretical study

Author: WuZuo
Tutor: WangKaiGe
School: Northwestern University
Course: Optics
Keywords: Femtosecond laser Pulse width Perturbation Density of energy state
CLC: O734
Type: Master's thesis
Year: 2011
Downloads: 1
Quote: 0
Read: Download Dissertation


Researching the theory that femtosecond laser damaged Si3N4 crystal, can provide theoretical support in the field of micro-machining etc, and both promote application prospect of femtosecond laser in a variety of areas,.it analysis and perfect in turn can also the interaction between femtosecond laser and Si3N4 crystal.In this paper, using perturbation theory combined the time and the energy state, the theory, of which the interaction between femtosecond laser and Si3N4 crystal, is deduced. The main contents are classified as follows:Firstly, because of pulse width of femtosecond laser is extremely short. Therefore, when discussing the interaction of femtosecond laser and Si3N4 crystal, the nonlinear process is discussed mainly. At the same time, this process is theoretically analyzed in detail. And to detailed analysis of the valence band electrons individual excitation, which may be contribute to absorption coefficients of the relevant model, of the valence band electrons as well as possible within the localized states.Furthermore, using steady state Boltzmann equation and the time-dependent perturbation theory, electronic relaxation time, that is, the time required for lattice back to the next equilibrium state, will be estimate roughly. And taking into account the change of a single electronic state, this amendment to the state’s distribution of lattice vibration, since the thermal effect of crystal depended primarily on the lattice vibration when is not extremely low. By courtesy of this consideration and mean spacing of adjacent pulse in comparison with average impulse width, and spacing can be properly adjusted in order to further impair crystal significantly different from the long pulse.Finally, Density of energy state can be approximated with method of spherical wave. As a basis, equation, of which electron density of conduction band was changed with time and energy, was simplified.

Related Dissertations

  1. Study of Data Reduction Technique Based on Manifold Learning,TP311.13
  2. Visual Quality Assessment between Different Ways Assisted Customized LASIK by OQAS,R779.63
  3. Frobenius nonlinear evolution equations integrable solutions and the expansion of integrable systems,O175.5
  4. Axial fan blade vibration non-contact measurement,TD441.2
  5. The Design of SIW Resonate Cavity and the Apply of Microwave Material’s Measure,TM931
  6. Large resonant frequency boost system selection and application,TM835
  7. Pulse width modulation based STATCOM under study,TM761.1
  8. Cascaded multilevel STATCOM control system,TM761
  9. One kind of PWM mode DC / DC buck converter Research and Design,TM46
  10. AC induction motor side inverter wind turbine research,TM464
  11. Detection and Parameters Estimation of Direct Sequence Spread Spectrum Communication Signals in Non-cooperative Context,TN914.42
  12. Approximate Analytical Solutions for Solving Linear and Nonlinear Second-Order Initial and Boundary Value Problems,O241.8
  13. Simulation of Flexible HVDC Transmission System,TM721.1
  14. Study on Power Supply of Electrostatic Precipitator Used in Coal-Fired Power,TM621.7
  15. Research on the Implementation of Reversible AC-DC-AC Variablefrequency Adjustablespeed System Based on DSP,TM921.51
  16. Asymptotic and Numerical Analysis for Several Classes of Singularly Perturbed Boundary Value Problems,O175.8
  17. Research on Structure and Control System of FDM Material Transmission Mechanism,TG659
  18. Molecular Dynamics Simulation of the Congeries of Alkylbenzene Sulfonate in Aqueous Solution,O643.1
  19. The Study on PMSM AC Servo Development Platform,TM341
  20. Metal Colouring with Femtoscond Laser Pulses,TN249

CLC: > Mathematical sciences and chemical > Crystallography > Crystal physics > The optical properties of the crystal
© 2012 www.DissertationTopic.Net  Mobile