THz Nonlinear Dielectrics

We experimentally investigate the dielectric response of two different liquid samples through nonlinear terahertz spectroscopy. Our results indicate that the nonlinear indexes of refraction of these liquids in the terahertz frequency range are up to six orders higher than those in the optical regime with an averaged value of 7.8±3×10
^-10
cm
²
/W for water and 1.30 ± 0.01×10
^-10
cm
²
/W for α-pinene.