Self-calibrating Tomography for Angular Schmidt Modes in Spontaneous   Parametric Down-Conversion
  We report an experimental self-calibrating tomography scheme for entanglement characterization in high-dimensional quantum systems using Schmidt decomposition techniques. The self-tomography technique based on maximal likelihood estimation was developed for characterizing non-ideal measurements in Schmidt basis allowing us to infer both Schmidt eigenvalues and detecting efficiencies. 
Stanislav Straupe, Denis Ivanov, Alexander Kalinkin, Ivan Bobrov,   Sergey P. Kulik and D.Mogilevtsev
quant-ph