Nonlinear optical coefficients in group IV and III-V semiconductors

In the low-frequency approximation, the magnitude of optical nonlinearities can be calculated exactly for conduction electrons from known band structure neark = 0, and approximately for the valence electrons on the basis of simple tetrahedral bonding orbitals. Reasonable agreement with experimental data has been obtained, both for second harmonic generation and for third order susceptibilities in Group IV and III-V semiconductors.