Bakunov M I, Tsarev M V, Mashkovich E A
University of Nizhny Novgorod, Nizhny Novgorod 603950, Russia.
Opt Express. 2012 Dec 17;20(27):28573-85. doi: 10.1364/OE.20.028573.
To circumvent a velocity mismatch between optical pump and terahertz waves in electro-optic crystals, we propose to use dual-wavelength optical beams tilted with respect to their planes of equal amplitude. The tilt is achieved by transmission of a dual-wavelength laser beam through a diffraction grating placed on the crystal boundary. The proposed technique extends optical rectification of tilted-front femtosecond laser pulses to difference-frequency generation with longer (nanosecond) pulses. Our analysis of the technique for LiNbO(3) pumped at 1.3 μm and GaAs pumped at 1.55 μm shows its efficiency.
为了规避电光晶体中光泵浦与太赫兹波之间的速度失配问题，我们建议使用相对于其等幅面倾斜的双波长光束。这种倾斜是通过将双波长激光束透过置于晶体边界的衍射光栅来实现的。所提出的技术将倾斜前沿飞秒激光脉冲的光整流扩展到了更长（纳秒）脉冲的差频产生。我们对在1.3μm泵浦的LiNbO(3)以及在1.55μm泵浦的GaAs的该技术分析表明了其有效性。
