Picture of wind turbine against blue sky

Open Access research with a real impact...

The Strathprints institutional repository is a digital archive of University of Strathclyde research outputs.

The Energy Systems Research Unit (ESRU) within Strathclyde's Department of Mechanical and Aerospace Engineering is producing Open Access research that can help society deploy and optimise renewable energy systems, such as wind turbine technology.

Explore wind turbine research in Strathprints

Explore all of Strathclyde's Open Access research content

Spin induced gigahertz polarization oscillations in vertical-cavity surface-emitting laser devices

Ackemann, Thorsten and Li, M. Y. and Jaehme, H. and Soldat, H. and Gerhardt, N.C. and Hofmann, M. R. (2011) Spin induced gigahertz polarization oscillations in vertical-cavity surface-emitting laser devices. In: Vertical-Cavity Surface-Emitting Lasers XV. Proc. SPIE, 7952 . UNSPECIFIED, 79520B.

[img]
Preview
PDF
Li_ProcSpie_7952_79520B_2011_spinosc.pdf - Submitted Version

Download (624kB) | Preview

Abstract

Spin-controlled vertical-cavity surface-emitting lasers (VCSELs) have been intensively studied in recent years because of the low threshold feasibility and the nonlinearity above threshold, which make spin-VCSELs very promising for spintronic devices. Here we investigate the circular polarization dynamics of VCSELs on a picosecond time scale after pulsed optical spin injection at room temperature. A hybrid excitation technique combining continuous-wave (cw) unpolarized electrical excitation slightly above threshold and pulsed polarized optical excitation is applied. The experimental results demonstrate ultrafast circular polarization oscillations with a frequency of about 11 GHz. The oscillations last inside the first undulation of the intensity relaxation oscillations. Via theoretical calculations based on a rate equation model we analyze these oscillations as well as the underlying physical mechanisms.