Spin-controlled vertical-cavity surface-emitting lasers (VCSELs) have several beneficial features, such as threshold reduction and circularly polarized lasing. We previously demonstrated 1-GHz switching between lasing circular polarizations with two opposite directions in a VCSEL based on a (110)-oriented multiple quantum well (MQW) with a degree of circular polarization higher than 0.9 . Shortening the carrier lifetime τc while preserving the electron spin relaxation time τs is a straightforward solution to switching the lasing circular polarizations faster since residual electrons in the MQW deteriorate the degree of spin polarization. We therefore introduced micropost structures in a (110)-MQW. However, we could not measure τs in microposts smaller than 2 μm due to the time resolution of the streak camera (∼25 ps) . Although use of the microposts with a fast non-radiative surface recombination is a promising approach for faster polarization switching in spin-controlled VCSELs, it is still unclear if τs in useful post sizes smaller than 2 μm can be kept long. In this work, we measured τc and τs in (110) GaAs/AlGaAs MQW microposts with special attention to those smaller than 2 μm using a pump probe-based time-resolved Kerr rotation (TRKR) technique. We also report the results of rate equation analysis in a micropost VCSEL using the measured τc and τs.
|Publication status||Published - 2013 Jan 1|
|Event||2013 Conference on Lasers and Electro-Optics Europe and International Quantum Electronics Conference, CLEO/Europe-IQEC 2013 - Munich, Germany|
Duration: 2013 May 12 → 2013 May 16
|Conference||2013 Conference on Lasers and Electro-Optics Europe and International Quantum Electronics Conference, CLEO/Europe-IQEC 2013|
|Period||13/5/12 → 13/5/16|
ASJC Scopus subject areas
- Electrical and Electronic Engineering