The optical losses in beam splitters vary based on their design. Devices with metallic coatings typically exhibit higher losses, while those with dichroic coatings can achieve minimal losses. The damage threshold is another critical factor, especially when used with. Our recent proof for the entanglement properties of states interfering with the vacuum on a beam splitter led to monotonicity and convexity properties for quantum states undergoing photon loss [Lupu-Gladstein et al. 03423 (2024)] by breathing life into a decades-old conjecture.