  Quantum processes involving single-photon states are of broad interest in
particular for quantum communication. Extending to continuous values a recent
proposal by Yuan et al \cite{YUAN16}, we show that single-photon quantum
processes can be characterized using phase randomized coherent states (PRCS) as
inputs. As a proof of principle, we present the experimental investigation of
single-photon tomography using PRCS. The probability distribution of field
quadratures measurements for single-photon states can be accurately derived
from the PRCS data. As a consequence, the Wigner function and the density
matrix of single-photon states are reconstructed with good precision. The
sensitivity of the reconstruction to experimental errors and the number of PRCS
used is addressed.
