Yousuke OTANI, Kouichi NITTA, and Osamu MATOBA^*

Department of Systems Science, Graduate School of System Informatics, Kobe University, Kobe 657-8501, Japan

(Received November 29, 2013; Revised February 28, 2014; Accepted March 31, 2014)

The possibility of multi-valued optical disk memory by using a convex-shaped recording mark fabricated by two-photon absorption is investigated. We fabricate a numerical model for convex-shaped recording marks and evaluate the signal characteristics in terms of the signal-to-noise ratio (SNR). The numerical results show that 6 bit data can be realized when the acceptable average SNR is 2 and a length of the mark is 4T.

Key words: optical disk memory, convex-shaped mark, multi-value

^*E-mail address: matoba@kobe-u.ac.jpx