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Title of Thesis

Nadeem Akram Ansari
Institute/University/Department Details
Department of Physics/ Quaid-i-Azam University, Islamabad
Number of Pages
Keywords (Extracted from title, table of contents and abstract of thesis)
four-wave mixing, cauchy-schwarz inequalities, bell's inequalities, higher-order squeezing, quantum-beat laser action, fokker-planck equation, three-mode laser

In this dissertation some Novel features of four-wave mixing are discussed and interesting results are predicted. These include violation of the Cauchy-Schwarz and Bell's inequalities, higher-order squeezing and two-level quantum-beat laser action.

A Fokker-Planck equation for the Q-representation of the field modes in the four-wave mixing processesis derived and its steady-state solution is presented. By using this solution the higher-order moments are evaluated and it is predicted that the Cauchy-Schwarz and Bell's inequalities are violated in non-degenerate four-wave mixing under suitable conditions. It is also shown that under suitable choice of parameters the amount of squeezing can be increased with the order of squeezing.

The theory of a two-level quantum-beat laser is presented. It is predicted that classical pump is responsible for coherence in such a way that the mean of the phase angles of the two side-modes is locked to a particular value. Thus the two-level quantum beat laser effect may occur which takes part in amplifying the four-wave mixing processes. The quantum fluctuations of the pump field is also considered in order to develop a quantum theory of a three-mode laser. It is shown that the pump field is not only responsible for the mode locking between the adjacent modes but it also creates coherence. The relative phase angle of the three modes is locked to a particular value. Thus the spontaneous emission noise is quenched from the relative phase angle and a two-level quantum-beat laser is obtained

Download Full Thesis
1289.28 KB
S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents
90.14 KB
2 1 Introduction 1
49.97 KB
  1.1 Non-Classical Effects In Four-Wave Mixing 1
  1.2 Two-Level Quantum-Beat Laser 4
  1.3 Quantum Theory Of A Three-Mode Laser 6
3 2 Non-Classical Effects In Non-Degenerate Four-Wave Mixing 8
377.58 KB
  2.1 Introduction 8
  2.2 Non-Classical Effects 11
  2.3 Density Matrix Equation Of Motion For The Field 24
  2.4 Fokker-Planck Equation And Its Exact Steady State Solution 36
  2.5 Non-Classical Effects In Four-Wave Mixing 40
  2.6 Discussion 51
4 3 Two-Level Quantum-Beat Laser 54
191.73 KB
  3.1 Introduction 54
  3.2 Review Of Three-Level Quantum-Beat Laser Density Matrix 55
  3.3 Equation For The Field Fokker-Planck Equation For The Field 61
  3.4 Modes 64
  3.5 Discussion 74
5 4 Quantum Theory Of A Three-Mode Laser 75
388.74 KB
  4.1 Introduction 75
  4.2 Equation Of Motion For The Density Matrix 76
  4.3 Study Of Diffusion Coefficients For The Relative Phase Angles 84
  4.5 Discussion 98
6 5 References 104
347.64 KB
  5.1 Appendix A 108
  5.2 Appendix B 114