Lecture
This lecture covers transverse cavity modes in laser systems, discussing resonator longitudinal modes, standing waves, degeneracy of modes, confocal resonators, and plane mirror resonators. It also explores TEMnmi modes, Gaussian amplitude, intensity profiles, phase factors, and the relationship between parameters and cavity design. The instructor explains the intensity profile, beam waist, and confocal parameter, as well as the Gouy phase effect. Laser oscillations are detailed, including the amplifier, resonator, pumping energy, and conditions for stable oscillations. The lecture delves into photon lifetime, quality factor, gain and losses in resonant cavities, threshold population inversion, rate equations, and gain saturation mechanisms.