Impact of Multi-Photon States on the Calibration of Single-Photon Detectors Using a Portable Bi-Photon Source - Pani, Sujeet; Earl, Duncan; Becerra, Francisco E. (2025 IEEE International Conference on Quantum Computing and Engineering (QCE), Quantum Computing and Engineering (QCE), 2025 IEEE International Conference on, QCE, 2025)