Robustness Analysis of Linear Time-Invariant Dynamic State Observers

1. Numerical Study of Auto-Control and Stabilization of
Pulse Repetition Rate of Passively Q-Switched Laser
Systems
Jala M. El-Azab Hamed M. Kandel and Mohamed A. Khedr
National Institute of Laser Enhanced Sciences, Cairo University, Egypt.
1www.icgst.com
http://www.icgst.com/paper.aspx?pid=P1111444352

2. In this work, a simplified technique to control and stabilize the passively Q-
switched laser pulses is proposed and denoted by automatic pulsed pumping
technique. The technique is applied to a diode-pumped Yb:YAG laser passively Q-
switched by Cr4+:YAG as saturable absorber by numerically solving the coupled
rate equations describing the system. The technique is based on the detection of
the generated Q-switched pulses which alter the pumping power either to be
switched off or set to a lower value depending on the selected modulation depth.
The system was pumped using different pumping techniques; continuous, pulsed
pumping and automatic pulsed pumping in order to compare the time stability of
the generated Q-switched pulses. The proposed technique has shown a good
control of the pulse repetition rate of Q-switched pulses with high stability. The
technique allowed high pulse repetition rate as similar to the pulsed pumping
scheme while maintained the time stability of the continuous pumping scheme
2www.icgst.com
http://www.icgst.com/paper.aspx?pid=P1111444352
Numerical Study of Auto-Control and Stabilization of Pulse Repetition Rate of Passively
Q-Switched Laser Systems
Abstract

3. 3www.icgst.com
Graduated from Faculty of Engineering, Electronics and Electrical Engineering Dept. ,
Cairo University. Received both the M.Sc. degree in nonlinear semiconductor laser
diodes in 2002 and the Ph.D. degree in chaotic semiconductor laser engineering in
2006 from National Institute of Laser Enhanced Sciences, Cairo University. Working on
modeling semiconductor laser diodes, chaotic optical communications, optical
networks, photonic crystal fibers, optical logic gates and holography applications.
Electronics and Electrical Engineering Dept. ,
Cairo University
http://eece.cu.edu.eg/

4. 4www.icgst.com
Hamed M. Kandel was born in Cairo, Egypt in 1980. Graduated from Faculty of Science, Chemistry & Physics
Dept., Cairo University in 2001. Received both the M.Sc. degree in theoretical study of X-ray laser in 2008
and the Ph.D. degree in short pulse solid-state laser modeling in 2014 from National Institute of Laser
Enhanced Sciences, Cairo University. Working on theoretical study of laser systems, ultra-short laser pulse
generation and control, generation of new laser wavelengths in XUV and X-ray range.
Faculty of Science, Chemistry & Physics Dept., Cairo University
http://cu.edu.eg/Faculty-News-Arch-21.html

5. 5www.icgst.com
Mohamed A Khedr was born in Kalubia, Egypt in 1956. Graduated from Faculty of Science, Physics Dept.,
Tanta University in 1978. Received both the M.Sc. in the physical phenomena of vacuum arc discharge in
1990and Ph.D. degrees in the micro hollow cathode discharge using Laser and mass spectroscopy in 1995
from physics Dept., Faculty of science Cairo University. Working in the dept. of Laser Science and its
Interaction with Matter National Institute of Laser Science Cairo University. Fields of interest; tunable
ultrafast laser systems, optical parametric oscillators, thin films, infrared optical detectors, Laser plasma
Acceleration.
Faculty of Science, Physics Dept., Tanta University
http://sci.tanta.edu.eg/English/Pages/default.aspx

6. 6

7. 6