Reduction in escape times of photogenerated charge carriers with asymmetric intrastep quantum wells and subsequent improvement in saturation optical intensity

Abstract

Escape times of photogenerated charge carriers from an InGaAsP intrastep quantum well (IQW) are calculated and compared with those from a conventional quantum well (QW). Since the red shift of the IQW is initiated at a higher electric field, the escape times from the IQW are smaller than those from the conventional QW at given values in modulator transmission. From the reduction in escape times, improvements in the exciton saturation intensity are estimated to be a factor of similar to 5 for both high and low modulator-transmission points.