Intersubband optical second-harmonic generation in multiple quantum wells: radiative coupling effects

An analysis of intersubband optical second-harmonic generation (SHG) in multiple quantum wells (QW´s) is presented, in which special attention has been paid to radiative coupling effects. Starting from the Maxwell-Lorentz equations, the field at the second-harmonic frequency in the QW system is determined. Following the same framework, the field at the fundamental frequency is also obtained. In a reflection geometry, the SH conversion efficiency is derived for a p-polarized incident field. Detailed numerical calculations for different numbers of QW´s, angles of incidence, as well as barrier thicknesses show that the SHG conversion efficiency can be significantly modified due to radiative coupling among wells