Schneider W, Ryabov A, Lombosi Cs, Metzger T, Major Zs, Fülöp J A, Baum P
Opt Lett. 2014 Dec 1;39(23):6604-7. doi: 10.1364/OL.39.006604.
Yb:YAG thin-disk lasers offer extraordinary output power, but systems delivering femtosecond pulses at a repetition rate of hundreds of kilohertz are scarce, even though this regime is ideal for ultrafast electron diffraction, coincidence imaging, attosecond science, and terahertz (THz) spectroscopy. Here we describe a regenerative Yb:YAG amplifier based on thin-disk technology, producing 800-fs pulses at a repetition rate adjustable between 50 and 400 kHz. The key design elements are a short regenerative cavity and fast-switching Pockels cell. The average output power is 130 W before the compressor and 100 W after compression, which at 300 kHz corresponds to pulse energies of 430 and 330 μJ, respectively. This is sufficient for a wide range of nonlinear conversions and broadening/compression schemes. As a first application, we use optical rectification in LiNbO₃ to produce 30-nJ single-cycle THz pulses with 6 W pump power. The electric field exceeds 10 kV/cm at a central frequency of 0.3 THz, suitable for driving structural dynamics or controlling electron beams.
镱铝石榴石（Yb:YAG）薄片激光器可提供非凡的输出功率，但能以数百千赫兹的重复频率输出飞秒脉冲的系统却很稀少，尽管这种状态对于超快电子衍射、符合成像、阿秒科学以及太赫兹（THz）光谱学而言是理想的。在此，我们描述了一种基于薄片技术的再生式Yb:YAG放大器，它能产生800飞秒脉冲，重复频率在50至400千赫兹之间可调。关键设计要素是一个短再生腔和快速开关普克尔盒。在压缩器之前平均输出功率为130瓦，压缩之后为100瓦，在300千赫兹时分别对应脉冲能量430和330微焦。这足以用于广泛的非线性转换以及展宽/压缩方案。作为首个应用，我们利用铌酸锂中的光整流，以6瓦泵浦功率产生30纳焦的单周期太赫兹脉冲。在中心频率0.3太赫兹时电场超过10千伏/厘米，适用于驱动结构动力学或控制电子束。
