New aspects of second-harmonic optical activity from chiral surfaces and interfaces

Abstract

New expressions are developed within the electric dipole approximation for the four Stokes parameters characterizing the polarization properties of coherent second-harmonic radiation generated from chiral isotropic surfaces in reflection. These are employed to derive, in addition to the three well-known incident circular polarization second-harmonic opticalactivity (SHOA) observables, thirteen new basic observables for the detection of surface SHOA which involve second-harmonic intensity difference measurements using right and left circular, and + 45 and - 45 linear, polarization modulation in the incident and second-harmonic radiation and in both simultaneously. Because of their dependence on a fully electric dipole allowed tensor these circular and linear intensity differences and the corresponding intensity sums have the same order of magnitude, so that all the dimensionless surface SHOA effects they generate are of the order of unity. The circular intensity differences (CIDs) depend on the imaginary p...