Detecting N-particle interference patterns with linear N-port analyzers

A standard two-path interferometer fed into a linear balanced N-port analyzer with coincidence detection of its output ports is analyzed. For unbound bosons it allows the detection of N-particle interference patterns with an N-fold reduction of the observed de Broglie wavelength and perfect visibility. Because the scheme involves heavy filtering, a lot of the signal is lost, yet, it is robust against common experimental imperfections and shows little noise. The proposal can be implemented with current technology.