A new chiral electro-optic effect: Sum-frequency generation from optically active liquids in the presence of a dc electric field

摘要

We report the observation of sum-frequency signals that depend linearly on anapplied electrostatic field and that change sign with the handedness of anoptically active solution. This recently predicted chiral electro-optic effectexists in the electric-dipole approximation. The static electric field givesrise to an electric-field-induced sum-frequency signal (an achiral third-orderprocess) that interferes with the chirality-specific sum-frequency atsecond-order. The cross-terms linear in the electrostatic field constitute theeffect and may be used to determine the absolute sign of second- andthird-order nonlinear optical susceptibilities in isotropic media.