Characterization of optically pumped quantum dot vertical – cavity structure

Abstract

Abstract The technology of spin optoelectronics has been used in the enhancement of laser technology, as well as the Vertical-Cavity Surface-Emitting Lasers (VCSELs) which are based on the quantum dot spin. The usage of these lasers in the field of spintronics offers a spin for carriers and highspeed of polarization switching thereby leading to high speed signal transfer. This report shows the fundamentals of spintronics and VCSELs. It also emphasizes the techniques used to analyze the laser light polarization output through the use of Stoke parameters. After that, the report discusses the experimental achievements, through the use of GaAs-based half- VCSEL pump having a wavelength of 905nm. The sample of the quantum dot from InAs/GaAs was subjected to the laser at room temperature in order to check its photoluminescence effects. The data obtained from a previous student were reanalyzed. The resultant output wavelength obtained from this was around 1300 nm, while the output peaks for luminescence corresponding to the wavelength with a width of 20.9 nm. The final section demonstrates the Stokes parameters of photoluminescence were taken at various power levels. However, due to the difficulties in the data interpretation, only the Stokes parameter at 200 mW pumping was carried out. The results indicate that there is a small spin memory on the order of 0.01 -0.02.