Electric field screening by photogenerated holes in multiple quantum wells: A new mechanism for absorption saturation

Abstract

We observe saturation in the electroabsorption of InGaAs/InP multiple quantum wells (MQWs) at high optical intensity. Contrary to the mechanism for zero-field MQWs, we find that saturation occurs due to the presence of trapped photogenerated holes that screen the MQWs from the applied electric field. By carefully measuring the absorption coefficient of the wells and the emission time for holes, we are able to fit the observed electroabsorption saturation with no adjustable parameters.