Fig. 1: Device, working principle and characterisation.
From: Time-bin entangled Bell state generation and tomography on thin-film lithium niobate
a Pump pulses are generated off-chip and input from the left via grating couplers; they undergo SPDC to generate the desired Bell state and probabilistically split to two twin Franson interferometers for tomography. Entanglement is maintained when photons propagate across two analysis interferometers where projection onto the desired bases occurs. GC grating coupler, VOA variable optical attenuator, φ projection phase, s signal, i idler. b Normalised second-harmonic interference measured by propagating a 1550 nm femtosecond laser backwards through device and setup. c SPDC generation probability versus off-chip average pump power.
