Experimental setup¶

The experimental configuration considered in the following calculation consists of a pumped type-II SPDC crystal (e.g. ppKTP) producing degenerate photons, followed by a compensation crystal to correct temporal walkoff between the horizontal and vertical components. The generated state is then rotated by a HWP at angle \(\vartheta\), spatially separated at a polarizing beam splitter (PBS), and finally measured by bucket detectors.

SPDC setup with HWP and PBS followed by bucket detectors