Quantization of electromagnetic field.

Separation of transverse and longitudinal component by gauge theory.

Hamiltonian of the transverse part in second quantization.

Dipole approximation of interaction of light with an atom.

Quantum states of the field.

Pure states of the field: states with a sharp number of photons, coherent states, squeezed vacuum and squeezed coherent state.

Mixed state of the field.

Thermal radiation, energy of thermal radiation, heat conduction by radiation.

Quantum optics of an atom.

Spontaneous emission, life time of excited state, natural spectral line shape, thermal and collisional broadening of spectral line, absorption and stimulated emission. Spectral hole burning, stimulated emission vs. absorption - laser equations.

Interaction of atoms with coherent light, reduced density matrix, relaxation in open systems, relaxation tensor, properties of relaxation tensor, spectral lines in susceptibility, absorption saturation, photon echo, slow light.

Quantum theory of electromagnetic radiation, interaction of light with matter, kinetic processes, introduction into spectroscopy and theory of open systems.