Fig. 6: Setup for quantum correlations transport experiment.

We generated correlated photon pairs in our quantum light source: a linearly polarized 405 nm laser beam passes through an optical isolator; the laser power is controlled by beams of a polarizing beam splitter. The laser pumps a periodically poled KTP crystal, where correlated photon pairs are generated via SPDC. We measured the photon pairs before (dashed line, CAM_in) and after propagating through the phase-separated fiber (PSF) (CAM_out). L_TALOF denotes the length of the PSF. We imaged the far-field of photon pair generation in the crystal onto the PSF input facet and captured the PSF output facet with the SPAD array camera. A bandpass filter before camera sensor rejects stray light. QWP quarter-wave plate, HWP half-wave plate, PBS polarizing beam splitter, OI optical isolator, LF long-pass filter (LF), ICO infinity corrected objective, BF bandpass filter. Focal lengths F_ICO, F_CAM, F₁, F₂, F₃, F₄ are discussed in the corresponding text.