Theory of second-harmonic generation upon reflection of light from a medium with a center of inversion
Agranovich V. M. , Darmanyan S. A.
New terms, in the same order in the field, are incorporated in the expression for the nonlinear polarization, which leads to second-harmonic generation, for inhomogeneous (bounded) media with a center of inversion. These new terms reconcile the theory with energy conservation. The new expression is used to find boundary conditions and the amplitudes of the second harmonic which arises upon the reflection of light from the boundary of an isotropic medium.