Extremely low-intensity optical nonlinearity in asymmetric coupled quantum wells.

Autor: Little, J. W., Whisnant, J. K., Leavitt, Richard P., Wilson, R. A.
Předmět:
Zdroj: Applied Physics Letters; 11/30/1987, Vol. 51 Issue 22, p1786, 3p
Abstrakt: We have observed an intensity-dependent shift in the exciton absorption features for a system of coupled quantum wells in which a thin barrier separates two wells of unequal widths. We found that for a fixed external bias on the sample, the normal quantum Stark shift of the excitons in the wells was suppressed when light of 1 μW/cm2 intensity was used to measure the absorption. The shift became systematically larger as the light intensity was decreased to as low as 100 pW/cm2. This extremely low-level nonlinearity may be due to internal fields that arise when free electrons and holes are separated within the coupled-well system. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index