High-order harmonic generation using quantum dots

使用量子点产生高次谐波

• 批准号: 387127256
• 负责人: Professor Dr. Helmut Zacharias
• 金额: --
• 依托单位: Russian Foundation for Basic Research
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/387127256?language=en
• 关键词: order; harmonic; generation; using; quantum

Femtosecond laser pulses enable the production of coherent XUV radiation via the process of high harmonic generation. While in continuous gas targets this is an established process, we want to investigate spatially structured plasmas and quantum dots as target materials at laser repetition rates of 1 kHz. The spatially structured target allows to increase the interaction length between the target material and the fundamental driving radiation. Usually this leads to an increased phase mismatch and eventually destructive interference between the fundamental and the generated XUV radiation. The spatial structuring allows in principle to suppress the harmonic generation with the opposite phase and via quasi-phase matching an increased XUV photon yield is expected. Parameters influencing the harmonic phase evolution in and between the individual plasmas will be studied. Further, the response of the individual emitters might be increased. A promising approach in achieving this is to switch from single atoms or ions to clusters of atoms as conversion media. Their increased extend is thought to increase the recombination probability of the returning electron which emits the harmonic field. Very small clusters - quantum dots - with a diameter of a few nm are expected to give best results, because in addition they show sharp electronic resonances. At the end a combination of both approaches, quantum dots in structured plasmas, will be studied.

飞秒激光脉冲能够通过高次谐波产生过程产生相干XUV辐射。虽然在连续气体靶中，这是一个既定的过程，但我们希望在1 kHz的激光重复频率下研究空间结构等离子体和量子点作为靶材料。空间结构化的靶允许增加靶材料与基本驱动辐射之间的相互作用长度。通常，这会导致相位失配增加，并最终导致基波和所产生的XUV辐射之间的相消干涉。空间结构允许在原则上抑制谐波产生与相反的相位，并通过准相位匹配的增加XUV光子产率是预期的。将研究影响单个等离子体内部和之间的谐波相位演化的参数。此外，可以增加各个发射器的响应。实现这一目标的一种有希望的方法是从单个原子或离子转换为原子簇作为转换介质。它们增加的延伸被认为增加了发射谐波场的返回电子的复合概率。直径为几纳米的非常小的簇-量子点-预计会得到最好的结果，因为它们还显示出尖锐的电子共振。最后，将研究两种方法的结合，结构化等离子体中的量子点。