Abstract

Calculations of nonlinear-optical-response coefficients of semiconductors are often plagued by nonphysical divergences as the frequencies of the incident light approach zero. We present a formalism to derive, in the independent-particle approximation, expressions for the electronic contributions to semiconductor nonlinear-optical susceptibilities that do not suffer from these unrealistic divergences. Our approach is much simpler and more transparent than another recently described scheme.¹ In addition to practical advantages for obtaining explicit susceptibility expressions, this simplification allows us to more easily understand the origin of nonphysical divergences in model calculations and how they may be avoided.

© 1995 Optical Society of America