Terahertz-field-induced optical second harmonic generation in isotropic media: theory and application

Abstract

We develop a theory of second harmonic generation of femtosecond laser radiation induced by the electric field of a copropagating terahertz pulse in an isotropic material. The theoretical predictions are verified experimentally. On the basis of the results obtained, we propose and experimentally demonstrate a new method to detect inhomogeneities in transparent materials.