Fig. 1: Schematics of the experimental setup.
From: High-quality photonic entanglement out of a stand-alone silicon chip
a Input laser with associated filter (TF) rejecting the amplified spontaneous emission and a polarization controller (PC). Laser light is injected in the ring resonator (RR) through the grating coupler and then propagates to a modal coupler (MC) and through the integrated pump filter (PF). b Schematic top view of one of the cascaded Bragg filter (BF) composing the PF. The output of the chip is connected to either a coincidence setup (c) with a beam splitter (BS) and bandpass filters to demultiplex signal and idler photons (TF signal/idler) or to the entanglement qualification setup (d) in a folded-Franson configuration. e Spectrum of the signal and idler filters, which exhibit 22 dB and 25 dB rejection for the two-FSR shift and three-FSR shift configurations, respectively.
