**PH-503 Lasers and Quantum Optics **

- Review of quantum mechanics, Dirac’s notation, Pauli spin matrices, electromagnetic waves and photons, wavelength and frequencies of electromagnetic radiation.
- Spontaneous and stimulated emission, absorption. Maser principle, cavity, gain medium, population inversion, Boltzmann statistics, threshold condition.
- Three-level laser, properties of a laser beams, black-body radiation theory. Modes of a rectangular cavity, Raleigh-Jeans and Planck radiation formula.
- Semi-classical treatment of the interaction of radiation and matter. Radiative transition rates, Interaction Hamiltonian, dipole approximation, rotating-wave approximation, electric dipole moment, allowed and forbidden transitions, ratio of the electric-dipole transition probability to the magnetic dipole transition probability, transition cross-section, absorption and gain coefficients.
- Line-broadening mechanisms. Homogeneous broadening, collision broadening and natural broadening. Wiener-Kinchine and Parseval’s theorem. Inhomogeneous and Doppler broadening.
- Rate equation approach to Laser theory, stationary solution, time-dependent solution, Gain, loss and saturation parameters, lasing condition.
- Ray and wave propagation in optical media. Matrix formulation of Geometrical optics. Wave reflection and transmission at a dielectric interface. Diffraction optics in paraxial approximation.
- Passive optical resonators, plane-parallel (Fabry-Perot) resonator, concentric, confocal, generalized spherical and ring resonator. Eigen-modes and Eigen-values. Stability condition, unstable resonator, photon lifetime and cavity Q.
- Q-switching, electro-optical, and acousto-optic Q-switches, saturable absorber Q-switch.
- Theory of mode-locking, active and passive mode-locking.
- Laser excitation techniques, optical, electrical, and chemical pumping, laser pumping, excitation transfer, meta-stable states and lifetimes.
- Types of lasers, solid-state, dye and semiconductor lasers, gas, chemical, free electron, and X-ray lasers, laser applications.

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**Recommended texts:**

*Principles of Lasers*, by Orazio Svelto, publisher: Plenum Press; 4th Edition, (1998).*Laser Fundamentals*, by William T. Silfvast, publisher: Cambridge University Press, (2004).