We present a VanderLugt-type optical phase-only correlator that uses t
he currently available liquid-crystal television. Theoretical and expe
rimental results show that phase mismatching and phase and amplitude c
ross coupling of the liquid-crystal television can reduce the peak int
ensity to approximately 60%-70%. The imperfect phase-only filter yield
s on-axis correlation with high light efficiency and utilizes all the
available space-bandwidth product of the liquid-crystal television.