Hiroomi GOTO^*, Tsuyoshi KONISHI, and Kazuyoshi ITOH

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

(Received July 15, 2008; Accepted January 5, 2009)

To cope with a larger intensity fluctuation of optical signals in optical communication networks, we have proposed and demonstrated an ultra-fast all-optical intensity equalizer based on an optical pattern recognition technique. To achieve higher transfer efficiency for this equalizer, we designed and fabricated a highly-efficient optical amplitude-phase filter using a diffractive optical element for optical pattern recognition. The fabricated amplitude-phase filter provides a diffraction efficiency of 85%, and the all-optical intensity equalizer is demonstrated to have higher transfer efficiency, when this filter is used.

Key words: optical communication, spatial optical filter, multiple-object discriminant filter, optical pattern recognition, optical equalizer, optical limiter

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