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Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE

Spin-diffracted four-wave mixing measurements of exciton spin relaxation and population transfer to dark states

S. Adachi, Suguru Maki, Osamu Ikeuchi, Hirotaka Sasakura, Shunichi Muto

Published Jun 2, 2003• 0 citations
Publisher

Abstract

We have observed the exciton spin relaxation processes in GaAs quantum wells at low temperatures by three-pulse spin-diffracted four-wave mixing measurements. After investigating the merits and demerits of this new method as compared with the pump-probe technique, we discuss the population transfer to the dark states through the measurements of the excitation-power dependence of exciton spin relaxation. Spin-diffracted four-wave mixing method is a powerful tool to investigate exciton spin dynamical processes where the pump-probe and time-resolved photoluminescence measurements have been used so far, since the method can be used in reflection geometry and be applicable to thin films and quantum dots.

DOI
10.1117/12.475704

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We have observed the exciton spin relaxation processes in GaAs quantum wells at low temperatures by three-pulse spin-diffracted four-wave mixing measurements. After investigating the merits and demerits of this new method as compared with the pump-probe technique, we discuss the population transfer to the dark states through the measurements of the excitation-power dependence of exciton spin relaxation. Spin-diffracted four-wave mixing method is a powerful tool to investigate exciton spin dynamical processes where the pump-probe and time-resolved photoluminescence measurements have been used so far, since the method can be used in reflection geometry and be applicable to thin films and quantum dots.
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