Accession Number : ADP007870

Title :   Fast State Filling Optical Nonlinearities with Charge Carrier Transport,

Corporate Author : HUGHES RESEARCH LABS MALIBU CA

Personal Author(s) : White, Jeff ; Kost, Alan ; Hasenberg, Tom ; Valley, George ; Garmire, Elas

Report Date : 22 MAY 1992

Pagination or Media Count : 4

Abstract : The effects of exciton saturation and state filling on the transmission of quantum wells can be extremely large and their onset is limited only by optical pulse length. On the other hand, recovery time is usually determined by the rate of electron-hole recombination, so that in high quality samples recovery may take tens of nanoseconds or longer. We have previously demonstrated that absorption saturation in quantum wells can be achieved at lower intensities by putting the quantum wells in the i-region of a hetero n-i-p-i structure. Here it is shown that the built-in fields of a hetero n-i-p-i can be used to sweep photocarriers out of quantum wells and reduce recovery times to the picosecond regime. This approach has advantages over methods to increase recombination rates such as the use of surface recombination which is not effective with quantum wells and ion bombardment which has a detrimental effect on excitons.

Descriptors :   *EXCITONS, *NONLINEAR OPTICS, ABSORPTION, ELECTRONS, FILLING, INTENSITY, ION BOMBARDMENT, LENGTH, QUALITY, RATES, SATURATION, STRUCTURES, SURFACES, CHARGE CARRIERS, ELECTRON TRANSPORT, LIGHT PULSES, SHORT PULSES, GALLIUM ARSENIDES.

Subject Categories : Optics
      Quantum Theory and Relativity

Distribution Statement : APPROVED FOR PUBLIC RELEASE