  We propose a method to perform the quantum state tomography (QST) of an
$\mathit{n}$-partite qudit state embedded in single photons using the
Hong-Ou-Mandel (HOM) interference between the target state and probe state.
This method requires only passive beam splitters for the HOM interference and
removes all active optical devices in the target modes to control the
measurement bases needed in conventional QST. Hence, it is applicable to
various degree of freedom of the target state without altering the measurement
setup. Moreover, a faithful estimation is realized even with classical probe
light such as laser and thermal light. As a proof-of-principle, we performed
the experimental demonstration using a polarization qubit. Regardless of the
photon statistics of the probe light, the estimated results of state
reconstruction are as accurate as those verified by conventional QST.
