2019, Vol.22, No.2, pp.177 - 189
A method of cavity dumping by the second harmonic generation that allows one to obtain
short and intensive pulses of laser radiation in the visible band is considered. It is based
on intracavity second harmonic generation in lasers with highly-reflective mirrors for the
fundamental frequency radiation. The second harmonic generation is obtained with the type
II crystal and is controlled with the use of a polarizer and a voltage-activated electrooptic
crystal inside the cavity. The method enables one to retain the laser beam quality and
propagation direction after transformation into the second harmonic.
The method may be implemented in solid-state laser systems operating in different modes:
mode-locking, Q-switching, and CW. Most effective second harmonic generation is realized
in the mode-locked lasers with ps-duration output pulses and peak intensity up to GW/cm2.
We propose a theoretical model and analysis of the cavity dumping by the second harmonic
generation in the mode-locked solid-state lasers that is based on the Herman A. Haus
approach. The dynamics of the pulse formation in the mode-locked regime is investigated; the
parameters of the output second harmonic pulses and their dependence on the main system
characteristics are determined. It is shown that the output pulse peak intensity, length, and
energy per unit area depend on the pump power and loss coefficient in the cavity: to obtain
pulses with higher intensity, energy and smaller length, the pump power should be increased
and losses decreased to the minimal value possible. One can obtain the output pulses with
the energies per unit area coming to several mJ/cm2. The output pulse parameters may also
depend on the dumping period. The cavity dumping repetition rate may be as high as MHz.
Key words: cavity dumping, second harmonic generation, mode locking, short laser pulses, Nd:YAG laser
Full text: Acrobat PDF (1334 KB)
Copyright © Nonlinear Phenomena in Complex Systems. Last updated: July 30, 2019