Control of laser light with nonlinear polarization mirrors
Nikola Ivanov Nikolov
Department of Informatics and Mathematical Modelling,
Building 321, Technical University of Denmark,
2800 Kongens Lyngby, Denmark
I. Buchvarov
University of Sofia, Quantum Electronics Department
5 J. Bouchier Blvd., 1164 Sofia, Bulgaria
Abstract:
A new method using frequency doubling polarisation mirror (FDPM), for passive
mode-locking and Q-switching of high power lasers have been proposed. The new
technique is based on the intensity dependent reflection of the FDPM, which is
due to the polarisation rotation of the fundamental wave in a nonlinear crystal
for second type (type II) second harmonic generation (SHG). The dependence of
the properties of the FDPM on the nonlinear charecteristics and the otientation
of the nonlinear crystal, as well as on the accumulated phase shift between the
second harmonic and the fundamental wave within the space between the nonlinear
crystal and the back reflector were investigated. Dynamics of the generation
evolution in laser with FDPM, using rate equations has been analized. This new
method has a very large spectral range, and the lack of absorption losses make
it appropriate for passive Q-switching of high evarage power lasers.