Abstract

Recent studies of dc and optical electric field effects on intersubband transitions in multiple quantum wells have yielded electro-optical and second-harmonic coefficients which are orders of magnitude larger than those of bulk semiconductors.^1,2 This is due largely to the giant growth-axis asymmetries which can be achieved using bandgap engineering. However, in previously-studied systems for which the conduction-band minimum is at the Γ-point, only the growthaxis component of the optical electric field couples to the intersubband transitions. The resulting requirement of non-normal incidence is inconvenient at best, and often introduces severe limitations to the practicality of devices.

© 1994 Optical Society of America