Abstract
High-order harmonic generation by a bicircular field, which consists of two coplanar counter-rotating circularly polarized fields of frequency and ( and are integers), is investigated for a polyatomic molecule. This field possesses dynamical symmetry, which can be adjusted to the symmetry of the molecular Hamiltonian and used to investigate the molecular symmetry. For polyatomic molecules having the symmetry, only the harmonics are emitted having the ellipticity . We illustrate this using the example of the planar molecules and , which obey the symmetry. We show that for the molecule, similarly to atoms with a ground state, there is a strong asymmetry in the emission of high harmonics with opposite helicities. This asymmetry depends on the molecular orientation.
- Received 5 July 2016
DOI:https://doi.org/10.1103/PhysRevA.94.033419
©2016 American Physical Society