Implementation of a polarization modulation technique in a photoluminescence and photoluminescence excitation measurement setup

摘要

We describe a polarization modulation technique employing a photoelastic modulator and present its implementation in the experimental setup of a photoluminescence (PL) and a photoluminescence excitation (PLE) experiment. In the PL experiment the technique is used to analyze the emitted light with respect to its polarization, whereas for the PLE the polarization of the exciting light is modulated, probing the polarization dependence of the absorption of the light. Since the modulation of the light is restricted to the polarization, the polarization dependence can be measured simultaneously with the PL or PLE intensity. The versatility and the sensitivity of the technique is exemplified by presenting results of polarized PL and PLE obtained on quantum wire samples grown on the vicinal (100) surface of GaAs by molecular beam epitaxy (MBE) that show a considerable anisotropy in the linear polarization for both the PL and PLE at low temperatures.