## Week |
## Topic |

1 |
Introduction to electrodynamics: Maxwell equations, vector and scalar potentials, presentation of the electromagnetic field as a superposition of the plane waves, electromagnetic field energy. |

2 |
Canonical variables, electromagnetic field as a superposition of harmonic oscillators, quantization of the field, photons. Thermal (black) radiation, Plank equation, Einstein theory of spontaneous and stimulated emission. |

3 |
Quantum theory of spontaneous and stimulated emission. Perturbation theory for probabilities of transitions. Electro-dipole transitions. |

4 |
Spontaneous emission, expression for the spontaneous emission probability. Oscillator strength. Introduction to line broadening. Natural broadening. |

5 |
Pressure (collisional) broadening for the quasi-static and impact approximations. Doppler broadening. |

6 |
Voigt function. Radiation transfer. Beer-Lambert law and expression for the absorption coefficient. Optically thick and thin layers. Self-reversal of the line. |

7 |
Rate equations. Three and four level systems. Conditions for population inversion in both systems. |

8 |
Gain saturation for the cases of Doppler and Lorentz broadening. Hole burning. Absorption spectroscopy in gases. |

9 |
Laser amplification. Amplifier as a filter: narrowing of the line in the amplifier. Amplification of the strong signal: homogeneous and inhomogeneous broadening. |

10 |
Laser oscillation. Self-excitation condition. Single and multimode oscillation for homogeneous and inhomogeneous saturation, respectively. Optical resonator modes, width of the mode, Q-factor. |

11 |
Power extraction in the case of homogeneous broadening. Small outcoupling and constant intraresonator intensity approximation. Optimal mirror transmission and optimal power. |

12 |
Rigrod model for the laser power in the case of the arbitrary outcoupling. Q-switching. |