Fig. 2

Experimental results of first-order superposition states. a. Superposition states presented on Bloch sphere. b. Measured modal structures of sent and received states with their identified relative phases. The double-headed arrow illustrates the identified orientation of modal structure with our angle recognition algorithm. It should be noticed that the identified orientation of modal structure reflects the relative phase of superposition state but does not equal to θ. c. Cross-talk matrix obtained by projecting each received state on all the sent states. The sent and received states are labeled by simulated modal structures for straightforward viewing. d. Projections on the mutually orthogonal states. e. Real-time fidelity measurement of first-order superposition states from i to viii