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Title of Thesis

Javed Anwar
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)
quantum statistical properties, noise, optical amplifiers, quantum optical systems, added noise, squeezed vacuum, phase fluctuations, squeeze parameter, noise-free amplification, three level laser

In this thesis we study the quantum statistical properties of noise in several quantum optical systems. In particular we study the quantum statistics of 'added noise' in linear amplifiers, the effect of 'squeezed vacuum' reservoir on the degenerate parametric oscillator and the quantum phase fluctuations in a three-level laser.

Quantum statistics of added noise in a two-photon linear amplifier is presented. The phase-sensitivity is introduced by preparing three-level atoms in a coherent superposition of atomic states. We have shown that, under certain conditions, the additive noise is squeezed whose squeezing parameter depends on the initial atomic variables.

The effect of the 'squeezed vacuum' reservoir on the degenerate parametric oscillator is studied. It is shown that when ordinary vacuum is replaced by a 'squeezed vacuum', the maximum 50 percent limit of second order squeezing inside the cavity can be crossed. The photon distribution function for the intracavity field is obtained and it is shown that, under certain conditions, the photon statistics of the intracavity field is identical to an ideal two-photon squeezed state.

A study of quantum phase fluctuations in a three-level laser in the 'squeezed vacuum' environment is presented. It is shown that the anisotropic distribution of the phase fluctuations associated with the 'squeezed vacuum' reservoir leads to the reduction in phase fluctuations created by the spontaneous emission. Under a stable phase locking condition the phase diffusion coefficient is obtained. It is shown that the phase diffusion coefficient depends on squeeze parameter. For larger value of squeeze parameter the phase diffusion coefficient vanishes.

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996.1 KB
S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents 0
83.71 KB
2 1 Introduction 1
94.58 KB
  1.1 Noise-Free Amplification 2
  1.2 Coherence in Atomic Systems 3
  1.3 Squeezed States of the Radiation Field 5
  1.4 Outline of the Thesis 7
3 2 Quantum Theory Of Linear Amplifiers 10
140.47 KB
  2.1 Introduction 10
  2.2 Linear Amplification Process 12
  2.3 Classification of the Amplifiers 16
  2.4 Atomic System 17
  2.5 Phase-Sensitive Amplification in a Degenerate Parametric Amplifier 22
  2.6 Conclusion 24
4 3 Quantum Statistical Properties Of Noise In A Phase-Sensitive Linear Amplifier 26
186.14 KB
  3.1 Introduction 26
  3.2 Noise-Free Amplification in a Two-Photon Phase Sensitive Amplifier 29
  3.3 Quantum Statistics of Added Noise Sensitive Linear Amplifier In a Phase representation 44
  3.4 Conclusion 47
5 4 Intracavity Field Squeezing In A Degenerate Parametric Oscillator 49
187.76 KB
  4.1 Introduction 49
  4.2 Degenerate Parametric Oscillator 52
  4.3 Fokker-Planck Equation and its Exact Steady-State Solution Using the Q Representation 59
  4.4 Higher Ordered Steady-State Squeezing 67
  4.5 Conclusion 70
6 5 Quantum Phase Fluctuations In A Three Level Laser 73
133.8 KB
  5.1 Introduction 73
  5.2 Density Matrix Equation of Motion 75
  5.3 Conclusion 88
7 6 Bibliography 89
312.46 KB
  6.1 Appendix A Reprint of "Effect of squeezing on the Degenerate Parametric Oscillator", Phys. Rev. A 45, 1804(1992) 97
  6.2 Appendix B Reprint of "Quantum Statistical Properties of Noise in a Phase Sensitive Linear Amplifier", Phys. Rev. A 48, (1993) 103