Second harmonic generation upon reflection of light from the surface of a solution of mirror-asymmetric molecules: A new tool for studies of molecular chirality

A new method for studying molecules with the chiral structure is proposed. The method is based on generation of the second optical harmonic (SH) upon reflection of light from the surface of solutions. It is shown that analysi s of the polarization dependence of the s component of the generated SH all ows one to detect chirality of molecules of the dissolved substance, to det ermine its relative value and sign, and to control the state of the surface of the sample under study. The advantage of this method is the fact that s mall amounts of substance are sufficient for its realization. Only the mole cules inside the interaction volume with the size determined by the diamete r of the waist of the excitation beam and the subwave thickness of the near -surface layer contribute to the SH signal.