

Title of Thesis
QUANTUM THEORY OF TWOPHOTON MICROMASER AND LASER 
Author(s)
IMRANA ASHRAF 
Institute/University/Department Details
Department of Physics/ QuaidiAzam University, Islamabad 
Session
1989 
Subject
Physics 
Number of Pages
120 
Keywords (Extracted from title, table of contents and abstract of thesis)
quantum theory, twophoton micromaser, laser linewidth, two â€“photon laser, multilevel micromaser 
Abstract In this dissertation, we study the quantum theory of twophoton micromaser and laser. To begin with, we study the photon statistics of the twophoton micromaser by considering the interaction of a quantized singlemode field with an effective twolevel atom through intermediate states. We present an exact solution for the photon distribution function and study the behaviour of mean photon number and photon number fluctuations. A periodic "collapse" and "revival" type behaviour is predicted. We find that the photon number fluctuations exhibits a periodic subPoissonian behaviour with respect to the interaction time. We then discuss the photon statistics of twophoton laser and derive an exact expression for photon distribution function. We find that photon distribution function for twophoton laser is wider than the Poisson distribution function. We also calculate the natural linewidth of a twolevel twophoton laser by using a FokkerPlanck approach. It is shown that, apart from a constant, the gain contribution to the laser linewidth is equal to the twophoton gain parameter and is independent of the mean number of photons in the field. Finally, we study the twophoton transitions in multilevel atomic system. In this case first we discuss the photon statistics of threelevel twophoton micromaser and laser. Then we consider the twophoton transition in fourlevel atomic system by considering dye laser as an example.






S. No. 
Chapter 
Title of the Chapters 
Page 
Size (KB) 





1 
0 
Contents 

75.39 KB 





2 
1 
Introduction 

61.75 KB 

1.1 
TwoPhoton Micromaser 
1 

1.2 
Two â€“Photon Laser 
4 

1.3 
TwoPhoton MultiLevel Micromaser And Laser 
5 





3 
2 
Photon Statistics Of A TwoPhoton Micromaser 

252.62 KB 

2.1 
Introduction 
9 

2.2 
Quantum Theory Of A SinglePhoton Micromaser 
10 

2.3 
Probability Amplitudes For The TwoPhoton Micromaser 
23 

2.4 
Photon Statistics Of A Two Photon Micromaser 
29 

2.5 
Linewidth Of A TwoPhoton Micromaser 
40 

2.6 
Discussion 
41 





4 
3 
Quantum Theory Of A TwoLevel TwoPhoton Laser 

192.49 KB 

3.1 
Introduction 
42 

3.2 
Review Of ScullyLamb Theory Of Laser 
43 

3.3 
Equation Of Motion For Reduced Density Matrix For The Field In The Two Photon Laser 
54 

3.4 
Natural Linewidth Of TwoPhoton Laser 
59 

3.5 
Discussion 
66 





5 
4 
TwoPhoton Transitions In MultiLevel Atoms 

459.92 KB 

4.1 
Introduction 
69 

4.2 
TwoPhoton Transitions In ThreeLevel Atom 
70 

4.3 
TwoPhoton Transitions In FourLevel System 
89 

4.4 
Discussion 
105 





6 
5 
References 
107 
166.25 KB 

5.1 
Appendix A 
111 

5.2 
Appendix B 
116 





