Electric field control of optical second-harmonic generation in a quantum well

We present theoretical predictions of the second-harmonic susceptibility due to an intersubband transition within the conduction band of a quantum well in an external applied electric field. The asymmetry of the quantum well due to the electric field accounts for the nonvanishing of the second-order susceptibilities. It is shown that for moderate values of an applied electric field of 10–70 kV/cm, the second-harmonic susceptibility is generally 10–100 times larger than that of bulk GaAs. Furthermore, this procedure of second-harmonic generation can be controlled by an external modulating voltage.