Rotation of polarization of a multiphoton state

A single polarized photon can be rotated to its orthogonally polarized state with an angle of π/2. For the state of N polarized photons in the same spatial mode, the rotation angle can vary between π/2N and π−π/2N for different states. Experiments on the two-photon states under different rotation operators are demonstrated in this Letter. The minimal rotation angle of π/4 is observed and the two photon de Broglie wavelength of λ/2 is shown.