Correlation measurement between the two photons measured with the setup shown in \ref{888919} b) and \ref{762069}. One of the rotatable polarizers stays at an angle \(\gamma \in \{ 0^\circ, 45^\circ, 90^\circ, 135^\circ \}\) while the other polarizer is rotated counter-clockwise in small steps between \(0^{\circ}\) and \(360^{\circ}\).