  Direct weak or strong measurement of quantum wave function has been
demonstrated based on the post-selection; however, the efficiency of the
measurement is greatly limited by the success probability of the
post-selection. Here we propose a modified scheme to directly measure photon's
wave function by simply inserting a liquid crystal plate after the coupling
between the pointer and wave function. Our modified method can significantly
increase the efficiency of the post selection. Numerical simulations
demonstrate that our proposal can have a greater efficiency in higher
resolution and higher fidelity.
