Realization of Arbitrary Inverse Unitary Transformation of Single Mode Fibre by Using Three Wave Plates

We report a method to realize the arbitrary inverse unitary transformation imposed by a single-mode fibre on photon's polarization by the succession of two quarter-wave plates and a half-wave plate. The process of realization is analysed on a Poincare sphere due to the fact that unitary transformation does not change the angle formed by polarization state vector. The method is meaningful in quantum communication experiment such as quantum teleportation, in which an unknown arbitrary quantum state should be kept to be unchanged in the case of using a single-mode fibre for time delay.