We implement an optical continuous phase-only composite
filter for security verification. An amplitude-mostly liquid crystal television
(LCTV) is used for input and a phase-mostly LCTV is used for the phaseonly
filter. We develop experimental techniques for optimizing the LCTV
modulations and analyze the diffraction of both coupled-mode LCTVs.
We use a new procedure for synthesizing the phase-only composite filters.
The filter produces a narrow correlation peak without sidelobes.
Experimentation results are shown.