title: Enhancement of photoacoustic emission through terahertz-field-driven electron motions.
abstract: We report the study of enhanced photoacoustic emission from a laser-induced plasma under the influence of the terahertz field up to 100 kV/cm. We theoretically and experimentally investigate the energy transfer from terahertz radiation to molecular translational motion, through terahertz-field-driven electron motion and inelastic electron-molecule collision. The enhanced photoacoustic emission in the frequency range of 1-140 kHz is quadratically dependent on the incident terahertz field. We also demonstrate, as an application, that the enhancement of photoacoustic emission from gases asymmetrically ionized by two-color laser field can be used for coherent terahertz wave detection.
authors.affiliation: Center for Terahertz Research, Rensselaer Polytechnic Institute, Troy, New York 12180, USA.
authors.forename: Jingle
authors.initials: J
authors.lastname: Liu
authors.forename: Benjamin
authors.initials: B
authors.lastname: Clough
authors.forename: X-C
authors.initials: XC
authors.lastname: Zhang