Nicholas Peters

In the context of telecommunications-wavelength fiberoptic resources, quantum-classical coexistence is considered an economical approach for efficient quantum networking, such as through (dense) wavelength-division multiplexing. However, inadequate filter isolation can introduce unwanted crosstalk noise. In this study, we investigate polarization-entangled photons contaminated by highly polarized classical signals, mapping them to maximally entangled mixed states (MEMS). Notably, MEMS can be effectively concentrated using a local filtering technique commonly referred to as the Procrustean method. To achieve this, we employ programmable polarization-dependent loss emulators (PDLEs), resulting in significant enhancements in the measured state fidelities.