Fig. 2: Experimental setup for the TFE SDC and TFE QI protocol.
From: Joint measurement of time–frequency entanglement via sum frequency generation
a Setup of the SFG feedback loop for the TFE SDC protocol. SFG: a χ(2) medium where the SFG process takes place; DM: a dichroic mirror to separate the generated pump photon from the photon pair; TTD: tunable time delay Δtextra; OSA: single-photon optical spectral analyzer. SM: switch mirror. After the signal and idler pass by the switch mirror SM, SM will flip and form a ring cavity. b Setup of the TFE QI protocol. Target: the target object to be detected, modeled as a unballanced beamspliter with reflection η (η = 0 when the object is absent), SP: short pass filter, MRPD: mode resolved single photon detector that detects pump photon generated in mode A0.
