Figure 2
From: A study of polarization compensation for quantum networks
Setup for polarization compensation using predefined photon polarization states. The laser power is controlled with the variable optical attenuator (VOA). The polarization of the photons entering the setup is defined using the polarizer (POL), in our case Wollaston prism. The flip mirror (FM) is used to switch between the signal from the setup for polarization compensation and the signal from the source of polarization-entangled photon pairs. Mechanical shutters are depicted as S1, S2, S3 and S4, beamsplitters as BS, polarization beamsplitter as PBS, half waveplates as HWP and single-photon detectors as D1 and D2 Solid lines are describing optical fibres and dashed lines free-space path of photons