  We propose a technique for performing quantum state tomography of photonic
polarization-encoded multi-qubit states. Our method uses a single rotating wave
plate, a polarizing beam splitter and two photon-counting detectors per photon
mode. As the wave plate rotates, the photon counters measure a
pseudo-continuous signal which is then Fourier transformed. The density matrix
of the state is reconstructed using the relationship between the Fourier
coefficients of the signal and the Stokes' parameters that represent the state.
The experimental complexity, i.e. different wave plate rotation frequencies,
scales linearly with the number of qubits.
