Abstract Ultrafast laser pulses spatially shaped as Bessel beams in dielectrics create high aspect ratio plasma channels whose relaxation can lead to the formation of nanochannels. We report a strong enhancement of the nanochannel drilling efficiency with illumination by double pulses separated by a delay between 10 and 500 ps. This enables the formation of nanochannels with diameters down to 100 nm. Experimental absorption measurements demonstrate that the increase of drilling efficiency is due to an increase of the confinement of the energy deposition. Nanochannel formation corresponds to a drastic change in absorption of the second pulse, demonstrating the occurrence of a phase change produced by the first pulse. This creates a highly absorbing, long-living state. Our measurements show that it is compatible with the semi-metallization of warm dense glass which takes place within a timescale of <10 ps after the first laser pulse illumination.

中文翻译：

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双超快贝塞尔脉冲对玻璃中能量沉积的纳米级限制

摘要 空间形状为电介质中贝塞尔光束的超快激光脉冲会产生高纵横比的等离子体通道，其弛豫可导致纳米通道的形成。我们报告了通过由 10 到 500 ps 之间的延迟分隔的双脉冲照明，纳米通道钻孔效率的显着增强。这使得能够形成直径低至 100 nm 的纳米通道。实验吸收测量表明，钻井效率的提高是由于能量沉积限制的增加。纳米通道的形成对应于第二个脉冲吸收的剧烈变化，表明发生了第一个脉冲产生的相变。这创造了一种高度吸收、持久的状态。