Polarization gating for high-harmonic generation in the vicinity of metal nanostructures

High harmonic generation (HHG) has attracted immense interest in the last decade due to its significant potential for applications. Recently demonstrated HHG in the vicinity of bowtie nanoantennae utilizes the high field enhancement provided by metal nanostructures, which allows HHG at unprecedented MHz repetition rates with pump intensities as low as 10¹¹ W/cm². Polarization gating is a powerful technique for single attosecond pulse generation, and its adaptation for the nanostructure-assisted HHG offers highly interesting perspectives for the generation of isolated attosecond pulses by low-intensity pump directly from laser resonators with MHz repetition rates. In this contribution, we theoretically study field enhancement, HHG, and generation of attosecond pulses by polarization gating in the vicinity of nanostructures which we have designed for this purpose.