Theoretical study of terahertz generation from atoms and aligned molecules driven by two-color laser fields

Abstract

We study the generation of terahertz radiation from atoms and molecules driven by an ultrashort fundamental laser and its second harmonic field by solving time-dependent Schrödinger equation (TDSE). The comparisons between one-, two-, and three- dimensional TDSE numerical simulations show that initial ionized wave-packet and its subsequent acceleration in the laser field and rescattering with long-range Coulomb potential play key roles. We also present the dependence of the optimum phase delay and yield of terahertz radiation on the laser intensity, wavelength, duration, and the ratio of two-color laser components. Terahertz wave generation from model hydrogen molecules are further investigated by comparing with high harmonic emission. It is found that the terahertz yield is following the alignment dependence of ionization rate, while the optimal two-color phase delays varies by a small amount when the alignment angle changes from 0 to 90 degrees, which reflects alignment dependence of attosecond electron dynamics. Finally we show that terahertz emission might be used to clarify the origin of interference in high harmonic generation from aligned molecules by coincidently measuring the angle-resolved THz yields.

References in corpus (4)

• Tailoring THz radiation by controlling tunnel photoionization events in gases
• Ticking terahertz wave generation in attoseconds
• Quantum mechanical approach to probing the birth of attosecond pulses using a two-color field
• THz generation by dual-color pulse in prealigned molecules

Cited by in corpus (4)

• Terahertz generation in dual-color laser: continuum electron in strong-field single-atom ionization
• Strong field ionization and gauge dependence of nonlocal potentials
• Coulomb potential determining terahertz polarization in two-color laser field
• A Study on Angular Distribution of THz Radiation Driven by Two-Color Laser-induced Microplasma