Figure 1
From: Massively Parallel Coincidence Counting of High-Dimensional Entangled States
Measuring the biphoton joint probability distribution with an EMCCD camera. (a) Experimental setup for measuring far-field type-I SPDC. (b–e) Flow chart of data processing. (b) The camera acquires many thresholded frames from which we calculate both (c) the average of all frames 〈\({C}_{i}\)〉 (indicated by 〈·〉) and (d) the average of the tensor product of each frame with itself 〈\({C}_{ij}\)〉 (⊗, Eq. (2)) (shown here for \(j=[{x}_{j}=70,\,{y}_{j}=33]\), indicated by the blue ×). Most coincidences are accidentals between photons from different pairs, yielding the apparent similarity between (c) and (d). Genuine coincidences from anticorrelated entangled photons appearing within the boxed region give a difference between the two (see insets). (e) The conditional probability distribution, via Eq. (4), shows anti-correlation of paired photons localized about \(i\) = [−70, −32].
