Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published November 11, 2022 | public
Journal Article

Mapping LiNbO₃ Phonon-Polariton Nonlinearities with 2D THz-THz-Raman Spectroscopy

Abstract

Two-dimensional terahertz-terahertz-Raman spectroscopy can provide insight into the anharmonicities of low-energy phonon modes—knowledge of which can help develop strategies for coherent control of material properties. Measurements on LiNbO₃ reveal THz and Raman nonlinear transitions between the E(TO₁) and E(TO₃) phonon polaritons. Distinct coherence pathways are observed with different THz polarizations. The observed pathways suggest that the origin of the third-order nonlinear responses is due to mechanical anharmonicities, as opposed to electronic anharmonicities. Further, we confirm that the E(TO₁) and E(TO₃) phonon polaritons are excited through resonant one-photon THz excitation.

Additional Information

The authors acknowledge the National Science Foundation CSDM-A program (Grant No. CHE-1665467) and NASA APRA program (Grant No. 80NSSC21K1467) for financial support. H. W. L. acknowledges financial support from the Ministry of Education of Taiwan. G. M. acknowledges financial support from the National Science Foundation Graduate Research Fellowship Program.

Additional details

Created:
August 22, 2023
Modified:
October 23, 2023