Laser physics PHYS-407

Laser Physics (PHYS-607)

The aim of the course is to describe the principles of lasers and laser action. The course covers interactions of atoms and molecules with light (absorption, emission and dispersion) and includes concepts such as Doppler, collision, and natural lifetime broadening, population inversion, and optical pumping. The principles of laser resonators and laser action (gain, threshold, power) are discussed. The course will treat some common types of laser in more detail, including continuous-wave (cw) and pulsed, gas and solid-state lasers and at the end, some laser applications will be discussed.

Learning Outcomes: At the end of this course, students should be able to:

Explain the operational principles and construction of lasers
Describe optical components that can be used to tailor the properties of the laser
Distinguish between the different optical cavities/resonators.
Describe the conditions of producing a laser beam.
Describe how pulsed laser beams can be obtained from a laser cavity.
Understand the laser applications in daily life.

Contents

Introduction to Lasers
Properties of laser beam
Electromagnetic waves and photons
Energy levels, Transition and spectral lines, The metastable level
Spontaneous and Stimulated emission, Stimulated Absorption
Line shape function
Black-Body Radiation
Relation between Einstein A and B Coefficients
Conditions for large stimulated emissions
Gain coefficient and threshold Gain coefficient
Line-broadening mechanism
Population inversion
The three and four-level system
Rate equations
Optical resonators
Conditions for steady state oscillation in a two mirror Resonator
Cavity resonance frequencies
Longitudinal and Transverse modes in a cavity
Pumping Process, Pulsed vs Continuous emission
Threshold condition and output power
Optimum output coupling
Laser tuning
Oscillation and pulsations in lasers
Q-Switching and mode-locking methods
Phase velocity and Group Velocity
Dispersion and Pulse Width
Non-linear crystals
Solid state lasers: Ruby Laser, Nd:YAG and Nd:Glass lasers
Semiconductor lasers: Homojunction lasers, Double Hetrostructure lasers
Gass Lasers: Helium Neon laser, CO2 laser, Nitrogen laser and Excimer laser
Free-Electro and X-ray lasers
Laser Applications.

Recommended Books

Laser Fundamentals by W. T. Silfvast, Cambridge University press, (2003).
Understanding lasers b y J. Hecht, Howard W. Sams & Company, USA (1988).
Lasers by P. W. Milonni and J. Eberly, Wiley, New York. (2010).
An Introduction to Lasers by M. N. Avadhanulu, S. Chand & company (2001).

Suggested Books

Principles of lasers by O. Svelto, Plenum press new York & London (1992).
Lasers by A.E. SiegmanUniversity, Science Books Mill Valley, C. A. (1986).
Laser Theory by H. Haken, Springer, Berlin (2003).
Lasers, Principles and Applications by J. Wilson and J. F. B. Hawkes, Prentice Hall, New York, (1988).
Lasers and Electro-Optics: Fundamental and Engineering by Christopher C. Davis, Cambridge University press, (1996).

ASSESSMENT CRITERIA