Stepanov A, Hebling J, Kuhl Juergen
Opt Express. 2004 Sep 20;12(19):4650-8. doi: 10.1364/opex.12.004650.
We demonstrate the use of a transient polarization grating induced by two femtosecond laser pulses propagating in a LiNbO3 crystal for the generation of frequency tunable, narrow-band, picosecond THz pulses. Employing pump pulses with 150 fs duration and 2 J energy, the generated THz pulse has an energy up to 1.8 pJ, a pulse duration of 3 - 5 ps and a bandwidth of 0.1 THz. The central frequency can be tuned in the range from 0.5 to 3 THz. The generation efficiency of the transient grating method in comparison to other techniques is discussed. The possibility of shaping the temporal waveform of the THz pulses by simply shaping the spatial intensity distribution of the pump pulses is demonstrated.
我们展示了利用在铌酸锂晶体中传播的两个飞秒激光脉冲诱导产生的瞬态偏振光栅来产生频率可调谐、窄带、皮秒级太赫兹脉冲。使用持续时间为150飞秒、能量为2焦耳的泵浦脉冲，所产生的太赫兹脉冲能量高达1.8皮焦耳，脉冲持续时间为3 - 5皮秒，带宽为0.1太赫兹。中心频率可在0.5至3太赫兹范围内调谐。讨论了瞬态光栅方法与其他技术相比的产生效率。证明了通过简单地对泵浦脉冲的空间强度分布进行整形来对太赫兹脉冲的时间波形进行整形的可能性。
