[OPTICAL REVIEW Vol. 12, No. 3 (2005) 242-246]
© 2005 The Optical Society of Japan

Design of a Label Recognition Filter for Crosstalk Suppression in a Label Recognition Unit using Optical Correlation Assuming the Assistance of Optical Time-Gating

Hideaki FURUKAWA*, Tsuyoshi KONISHI and Kazuyoshi ITOH

Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan

(Received September 30, 2004; Accepted March 9, 2005)

To suppress crosstalk caused by matched filtering in label recognition based on optical correlation, we propose the novel design method of a label recognition filter to improve the discrimination performance. Assuming the assistance of optical time-gating, the label recognition filter is designed by a technique of a multiple-object discriminant filter (MODF) so that the crosstalk can be suppressed only at the center of correlation signals. This method can reduce the requirement for the performance of an optical thresholder. Simulation results show that the designed label recognition filter can successfully suppress the crosstalk.

Key words: optical label recognition, optical correlation, time-space conversion, optical time-gating, multiple-object discriminant filter

*E-mail address: furukawa@photonics.mls.eng.osaka-u.ac.jp