Study of nonlinear polarization density as a function of some media characteristics
Other Title(s)
دراسة كثافة الاستقطاب اللاخطي بدلالة بعض خصائص الوسط
Dissertant
Thesis advisor
al-Kamil, Abd al-Munim Khalil
al-Zahir, Tariq Abd al-Rida
Comitee Members
al-Birmani, Muhammad Jafar Fadil
al-Nakishli, I. S.
Husayn, Ali A.
Salman, Jamal Wahhab
Majid, Rad Hamid
University
University of Baghdad
Faculty
College of Education for Puresciences-IBN al-Haitham
Department
Department of Physics
University Country
Iraq
Degree
Ph.D.
Degree Date
2005
English Abstract
Bloch equations have been used to evaluate the medium nonlinear polarization density behaviour, according to the quantum theory.
The medium has been represented as a two- level system.
In this representation, matrix density formula has been described the two levels coupling, under rotating wave approximation (RWA).
A computer code has been written to solve numerically Bloch equations simultaneously, using Runge-Kutta-Fehlberg method.
A bench mark problem has been used succeffely to check the computer code accuracy; the output results mirror those published.
Our code has been utilized to study the effect of longitudinal relaxation time on the medium nonlinear polarization density behaviour at exact and non-exact resonance cases of wave-matter interactions.
Concerning that, nonlinear polarization density behaviour shows fast build-up at the initial interaction time, and then decay at later time to approch saturation ( minimum values of nonlinear polarization density) at last time.
The decay in the non-exact resonance interaction is larger than that in the exact resonance.
The effect of frequency detuning (Δ) ( it is detuning between the transition frequency Wba and the fundamental wave frequency W0 ) on the nonlinear polarization density behaviour has been studied.
It appers that, the nonlinear polarization density decreases when the interaction becomes far away from exact resonance.
Finally, the effect (ratio of longitudinal relaxation time to transverse relaxation time), on the response time of the nonlinear medium and how long does the medium obeay the nonlinearity.
It has been observed from the study that at certain limit values of , the response time will increase while increasing .
After these values, the increasing of will possesse very little effect on the nonlinear response time.
Main Subjects
No. of Pages
103
Table of Contents
Table of contents.
Abstract.
Chapter One : Introduction.
Chapter Two : Theory.
Chapter Three : Numerical analysis and programming.
Chapter Four : Calculations, results and discussion.
References.
American Psychological Association (APA)
Ali, Abd al-Karim Mahdi Salih. (2005). Study of nonlinear polarization density as a function of some media characteristics. (Doctoral dissertations Theses and Dissertations Master). University of Baghdad, Iraq
https://search.emarefa.net/detail/BIM-755565
Modern Language Association (MLA)
Ali, Abd al-Karim Mahdi Salih. Study of nonlinear polarization density as a function of some media characteristics. (Doctoral dissertations Theses and Dissertations Master). University of Baghdad. (2005).
https://search.emarefa.net/detail/BIM-755565
American Medical Association (AMA)
Ali, Abd al-Karim Mahdi Salih. (2005). Study of nonlinear polarization density as a function of some media characteristics. (Doctoral dissertations Theses and Dissertations Master). University of Baghdad, Iraq
https://search.emarefa.net/detail/BIM-755565
Language
English
Data Type
Arab Theses
Record ID
BIM-755565
