Phonon-Mediated Third-Harmonic Generation in Diamond

TL;DR

This paper demonstrates how resonant phonon excitation in diamond can strongly modulate third-harmonic generation, enabling control over nonlinear optical responses through phononic interactions.

Contribution

It introduces a novel mechanism for third-harmonic generation mediated by resonant Raman phonons, with tunable enhancement or suppression.

Findings

Third-harmonic generation can be enhanced or suppressed by six orders of magnitude.

Interference between electronic and phonon-mediated contributions controls the nonlinear response.

Resonant phonon excitation enables dynamic control of optical properties in diamond.

Abstract

We observe strongly anisotropic third-harmonic generation mediated by resonant sum-frequency driving of Raman phonons with THz light, extending light-induced dual control of structural and optical properties in solids. Either strong enhancement or strong suppression of the third harmonic covering six orders of magnitude can be achieved, a result of interference between purely electronic and phonon-mediated contributions to the polarization field. These findings enrich capabilities for tailoring nonlinear optics via phononics and for the spectroscopy of crystalline structural dynamics.