Generation of sub-30-fs pulses from a scaleable high-energy oscillator
Generation of sub-30-fs pulses from a scaleable high-energy oscillator
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从可扩展的高能振荡器生成低于 30fs 的脉冲
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
F. Krausz
中科院分区：
文献类型：
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作者：
A. Fuerbach;Alma d. C. Fernandez Gonzalez;A. Apolonski;E. Seres;T. Fuji;F. Krausz
我们报道了从镜色散控制(MDC)钛宝石振荡器中产生亚30fS脉冲，该振荡器包含一个用于增加腔长的多程Herriott腔。使用该方案，可以实现低至几兆赫的重复频率。为了避免多重脉冲不稳定性，我们在一个非常宽的波长范围内以轻微的正群延迟色散(GDD)方式运行激光器。这会导致强啁啾光脉冲的形成，降低激光晶体内部原本非常高的峰值强度，这将限制最大输出能量。我们借助著名的SPIDER技术研究了与这些脉冲相关的光谱相位，并根据结果构造了一个优化的压缩器。当用10W的倍频激光(相干Verdi V10)泵浦时，可获得远高于200nJ的输出能量。由于没有观察到不稳定性的迹象，我们相信，如果使用更强大的泵浦激光，我们的方法可以扩展到更高的能量。由于具有良好的光束轮廓，可以演示各种材料的高分辨率微加工，包括透明电介质。将给出透明材料亚微米表面改性的结果。
We report on the generation of sub-30fs pulses from a mirror-dispersion-controlled (MDC) Ti:sapphire oscillator, containing a multiple-pass Herriott-cell for increasing the cavity length. Using that scheme, repetition rates down to some few MHz could be achieved. To avoid multiple pulsing instabilities, we operate the laser in a regime of slight positive group-delay dispersion (GDD) over a very broad wavelength range. This results in the formation of strongly chirped light pulses, reducing the otherwise very high peak-intensity inside the laser crystal, which would limit the maximum output energy. We have investigated the spectral phase associated with these pulses with the help of the well known SPIDER-technique, and, based on the results, have constructed an optimized compressor. When pumped with the full 10 W of a frequency-doubled Nd:YVO4 laser (Coherent Verdi V10), output energies well above 200 nJ could be obtained. As no signs of instabilities were observed, we believe, that our approach is scaleable to even higher energies if more powerful pump lasers are used. Thanks to the excellent beam profile, high-resolution micromachining of various materials, including transparent dielectrica could be demonstrated. Results on sub-micrometer surface modification of transparent materials will be presented.