  Bell-state analysis is a considerable challenge and an essential requirement
for reliable implementation of quantum communication proposals. An open
question is the one for the maximal fraction of successful Bell measurements.
It has been pointed out that no scheme using only linear elements can implement
a Bell state analyzer. Some effort has paid attention to the complete
polarization-entangled Bell-state analysis using linear optics, with the aid of
auxiliary means. Here we present a symmetry-broken scheme with linear optics
only, without any aid of other auxiliary means, for discriminating
polarization-entangled Bell states. Although our scheme is unable of realizing
complete Bell-state measurement for less photon-pairs situation, it can
deterministically identify four Bell states with success probabilities beyond
99.2% provided that photon-pairs are not less than 8. Our scheme as a
significant breakthrough is simpler and feasible with respect to the current
technology for the near-complete Bell-state analysis. Symmetry breaking is
indispensable in our scheme as in other physical systems.
