Valence-subband nonparabolicity is shown theoretically to lead to nonlinearities associated with terahertz third-harmonic generation in strained <i>p</i> -type quantum wells. For strained InAs quantum wells it is found that the corresponding value of χ<sup>(3)</sup> can be as large as ~10<sup>-12</sup>(m/V)<sup>2</sup>. The predicted values of χ<sup>(3)</sup> are in the range of those associated with intersubband transitions in the mid-infrared region of the spectrum.
© 2001 Optical Society of America
D. S. Citrin, "Terahertz nonlinear optics with strained p-type quantum wells," Opt. Lett. 26, 554-556 (2001)