Measuring the complex Joint Spectral Amplitude of photon pairs with a compact silicon chip

Stimulated Emission Tomography (SET) is a technique which maps the Joint Spectral Amplitude (JSA) of photon pairs with extremely high signal to noise ratio and low integration times. While the modulus of the JSA is easy to access, the retrieval of the Joint Spectral Phase (JSP) is far more challenging and requires advanced interferometric techniques. Here we present and validate a scheme to measure the complex JSA by using a reconfigurable silicon chip. In particular, we map the rich structure of the JSP of a silicon microresonator.