Fig. 1. Experimental setup. (a) Schematic diagram of a portable polarization entangled photon pair source; (b) ABS packaged F1 and FPBS1; (c) ABS packaged dual channel filter

Fig. 2. Joint spectral intensity maps. (a) Theoretically calculated results; (b) experimentally measured results, the red dotted line in the figure represents the filter bandwidth used

Fig. 3. Portable polarization entangled photon pair source physical diagrams. (a) Internal diagram; (b) appearance diagram

Fig. 4. Analytical devices. (a) Polarization analysis device; (b) long-distance distribution of polarized entangled photon pairs over 100 km

Fig. 5. Output characteristics of entangled photon pairs. (a) Relationship between signal channel counting rate and pump power, where the dash represents the primary term, representing the Raman photon, the dotted line indicates the quadratic term, representing the four-wave mixing photon; (b) the relationship between the coincidence counting rate and the pump power and the coincidence-to-accidental ratio and the pump power, among them, the red square dot represents the conformance counting rate, corresponding to the left y-axis, and the green dot represents the coincidence-to-accidental ratio, corresponding to the right y-axis

Fig. 6. Polarization entanglement characteristics of photon pairs. (a) The change of single-channel counting rate with relative declination angle; (b) the coincidence counting rate varing with relative declination angle, the red dots are the measured coincidence counting rate, and the solid blue lines are the fitted curves

Fig. 7. Entanglement characteristics of photon pairs after distributing over 100 km. (a) The change of single-channel counting rate with relative declination angle; (b) The coincidence counting rate varing with relative declination angle, the red dots are the measured coincidence counting rate, and the solid blue lines are the fitted curves