Generation of an Isolated Attosecond Pulse in the Far Field by Spatial Filtering with an Intense Few-Cycle Mid-infrared Laser

Abstract

AbstractAs discussed in Sect. 1.4.1, high-order harmonic generation (HHG) has been widely used to produce attosecond pulses in the extreme ultraviolet (XUV) or soft X-ray [1–3]. Due to its great potential for probing ultrafast electronic processes, there is a plethora of techniques available to generate an isolated attosecond pulse (IAP), with the idea that high harmonics be generated from half an optical cycle only in a few- or multi-cycle infrared laser pulse. Since the harmonic field generated by all atoms within the laser focus co-propagates with the fundamental laser pulse in the gas medium, as well as the possible further propagation in free space depending on the experimental setup, any methods using HHG to generate the IAP also need to take the effects of macroscopic propagation of fundamental and harmonic fields into account. As demonstrated in Chaps. 3 and 4, these effects have been well taken care by using the well-established propagation theory with the quantitative rescattering (QRS)-based single-atom induced dipoles, the phase of high harmonic which is inevitably involved in the propagated harmonic field plays an essential role for the attosecond pulse generation. In this chapter, I will focus on the generation of attosecond pulses, which allows one to test the phase of high harmonic in previous studies as well.KeywordsHigh HarmonicSpatial FilterAttosecond PulseHigh Laser IntensityHarmonic FieldThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.