Abstract
In this paper we report an in-depth study of the nonlinear optical properties associated with intersubband transitions in AlInAs/GaInAs coupled quantum wells grown by MBE. Structures with giant nonlinear susceptibilities (Chi) <SUP>(2</SUP>)(2 (omega) ) and (Chi) <SUP>(3</SUP>)(3 (omega) ) (compared to the bulk constituents of the quantum wells) have been designed and demonstrated. They exhibit large linear Stark shifts of the intersubband transitions which have been used to efficiently tune the nonlinear susceptibilities. The second order nonlinear susceptibility (Chi) <SUP>(2</SUP>)(2 (omega) ) exhibits a peak as a function of the electric field corresponding to the energy levels being made equally spaced via the Stark effect. In a three-coupled-well structure triply resonant third harmonic generation has been observed. The corresponding (Chi) <SUB>(3 (omega</SUB> ))<SUP>(3</SUP>) (10<SUP>-14</SUP>(m/V)<SUP>2</SUP> at 300 K and 4 X 10<SUP>-14</SUP> (m/V)<SUP>2</SUP> at 30 K) is the highest measured in any material. The equivalent of multiphoton ionization of a molecule has also been investigated in this structure.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have