Ghotbi M, Beutler M, Petrov V, Gaydardzhiev A, Noack F
Max-Born-Institute for Nonlinear Optics and Ultrafast Spectroscopy, Berlin, Germany.
Opt Lett. 2009 Mar 1;34(5):689-91. doi: 10.1364/ol.34.000689.
We report efficient generation of tunable femtosecond pulses in the near IR using a two stage, white-light seeded, collinear, femtosecond optical parametric amplifier (OPA). The OPA, based on BiB(3)O(6) crystal in both stages and pumped at 807 nm by a 1 kHz Ti:sapphire laser amplifier, provides sub-30 fs signal pulses after compression with energies exceeding 200 microJ, which corresponds to fivefold pulse shortening and approximately 30% internal conversion efficiency in the second stage considering 150 fs pump pulses with 1.5 mJ energy. The corresponding idler pulses with more than 100 microJ have sub-60 fs duration without compression. The first stage alone is capable of producing sub-20 fs pulses near 1400 nm at the microjoule level without using any compression.
我们报道了利用两级白光种子共线飞秒光学参量放大器（OPA）在近红外波段高效产生可调谐飞秒脉冲的方法。该OPA两级均基于BiB(3)O(6)晶体，并由1 kHz钛宝石激光放大器在807 nm波长处泵浦，压缩后可提供能量超过200 μJ、脉宽小于30 fs的信号脉冲。考虑到150 fs、能量为1.5 mJ的泵浦脉冲，这相当于在第二级实现了五倍的脉冲压缩以及约30%的内转换效率。相应的闲频脉冲能量超过100 μJ，未压缩时脉宽小于60 fs。仅第一级就能在不使用任何压缩的情况下，在微焦耳量级产生波长接近1400 nm、脉宽小于20 fs的脉冲。
