Abstract This paper demonstrates an approach that negative uniaxial crystal
has a relative anomalous dispersion effect which can compensate group
velocity delay, and applies this approach to nonlinear frequency
conversion of an ultrafast laser field. High efficiency of the third
harmonic generation is experimentally fulfilled by adopting a
collinear configuration of doubing-compensation-tripling system.
Through finely adjusting the incident angle and optical axis direction
of the compensation plate, it obtains ultraviolet (UV) output energy of
0.32~mJ centered at 270~nm with spectral bandwidth of 2~nm when
input beam at 800~nm was 70~fs pulse duration and 6~mJ pulse energy
which was extracted from Ti:sapphire laser system by a diaphragm,
corresponding to an 800-to-270~nm conversion efficiency of 5.3%
and a factor-of-1.6 improvement in the third harmonic generation of
UV band in comparison with a general conventional configuration.
Furthermore, when the full energy of 18~mJ from a Ti:sapphire laser system
was used and optimized, the UV emission could reach 0.83~mJ.
Received: 16 December 2008
Revised: 26 February 2009
Published: 20 October 2009
(Ultrafast processes; optical pulse generation and pulse compression)
(Frequency conversion; harmonic generation, including higher-order harmonic generation)
Fund: Project supported by the National
Basic Research Program of China (Grant No 2006CB0806001), the
Program for Changjiang and Innovative Research Team in University,
Shanghai Leading Academic Discipline Project (Grant No B408).
Cite this article:
Wang Yan-Ling, Zhou Xu-Gui, Wu Hong, Ding Liang-En Efficient collinear frequency tripling of femtosecond laser with compensation of group velocity delay 2009 Chin. Phys. B 18 4308