We theoretically analyze type-I broadband second-harmonic generation (SHG) of femtosecond laser pulses based on a quasi-phase-matching configuration in periodically poled congruent
(LN) and periodically poled
(PPMgLN) (5% and 7%).
Group-velocity matching (GVM) can be achieved at the fundamental waves of 1.59, 1.56, and
for SHG when the three types of crystals have grating periods of 22.31, 20.07, and
respectively. It is found that the central wavelength of the fundamental wave for GVM will increase with the decrease of MgO doping in
. It is concluded that the shift of the GVM central wavelength is due to the difference of MgO doping, which changes the dispersion of the crystal.
Therefore, tunable and high efficiency broadband SHG of femtosecond laser pulses in a long crystal can be realized by selecting different doping rates of PPMgLN.
© 2007 Optical Society of America
(190.2620) Nonlinear optics : Harmonic generation and mixing
(190.4400) Nonlinear optics : Nonlinear optics, materials
Original Manuscript: May 15, 2007
Revised Manuscript: August 3, 2007
Manuscript Accepted: September 18, 2007
Published: November 1, 2007
Junfeng Zhang, Yuping Chen, Feng Lu, Wenjie Lu, Weirui Dang, Xianfeng Chen, and Yuxing Xia, "Effect of MgO doping of periodically poled lithium niobate on second-harmonic
generation of femtosecond laser pulses," Appl. Opt. 46, 7792-7796 (2007)