Discrimination of All Types of 4-Bit Optical Code by Optical Time-Gating and Designed Label Recognition Filter in Label Recognition Using Optical Correlation

In label recognition based on optical correlation processing, to completely discriminate a 4-bit target optical code from all types of 4-bit nontarget ones, we propose a novel label recognition method using both optical time-gating and the designed label recognition filter. We experimentally demonstrate that the intensities of correlation signals of 4-bit similar optical codes can be suppressed by the designed label recognition filter and that only the correlation signal of a 4-bit target optical code can be detected by extraction with optical time-gating. The optical time-gating is realized by using organic nonlinear optical crystal: 2-adamantylamino-5-nitropyridine (AANP).