“…Quantum entanglement [1] has been considered as an essential asset to quantum communication and computation tasks. Bell states analysis (BSA), which is defined as the projection of two qubits onto maximally entangled states, is a crucial element in many important quantum information processing tasks, including measurement-based quantum computation [2,3], quantum teleportation [4,5], entanglement swapping [6,7], quantum dense coding [8][9][10], quantum key distribution [11][12][13][14][15][16][17], entanglement concentration [18][19][20], and quantum secure direct communication [21][22][23][24][25][26][27]. However, it is fail to unambiguously discriminate all of the four single degree of freedom (DOF) shared Bell states with only linear optical elements [28,29], which is called a complete linear optical BSA for photonic system.…”