Ultrashort Laser Pulse Phenomena, 2nd Edition

Circulating Pulse Model 293

spectrum of gains and losses). The bandwidth limit of the amplifier medium

has been reached in some (glass lasers, Nd:YAG lasers), but not all, lasers.

Other pulse width limitations arise from higher-order dispersion of optical com-

ponents and nonlinear effects (four wave mixing coupling in dye jets, two photon

absorption, Kerr effect, etc…).

The pulse evolution in a cw pumped laser leads generally to a steady state,

in which the pulse reproduces itself after an integer number of cavity round trips

(ideally one). The pulse parameters are such that gain and loss, compression and

broadening mechanisms, as well as shaping effects, ...