Circular polarization characteristics in vertical-cavity surface-emitting lasers (VCSELs) with InAlGaAs quantum wells injected by spin-polarized electrons were investigated. A degree of circular polarization of 10% was obtained in a reduced birefringence VCSEL at a lasing wavelength of 1544 nm at room temperature under optical pumping of spin-polarized electrons. Strong birefringence originally introduced to stabilize the lasing polarization was confirmed to be undesirable for a high degree of circular polarization in spin-injected VCSELs. A spin-flip rate equation analysis fairly reproduced the experimental results and supported our conclusions.
- InAlGaAs quantum well
- Vertical cavity surface emitting laser
- electron spin
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering