Generation of subdiffraction limit optical patterns using a diffractive optical element and its application to microscale secret sharing scheme

2016 Fiscal Year Final Research Report

• Project/Area Number: 26390084
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Optical engineering, Photon science
• Research Institution: Osaka University
• Principal Investigator: Ogura Yusuke 大阪大学, 情報科学研究科, 准教授 (20346191)
• Research Collaborator: AINO Masahiko
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 回折光学素子 / 回折限界 / 暗号化

Outline of Final Research Achievements

This study aims at developing a method for generating subdiffraction limit optical patterns, which contain an optical pattern finer than the diffraction limit spot, using propagating light. We designed a diffractive optical element that generated an array of subdiffraction limit spots using our own algorithm. Experimental results showed that various arrangements of subdiffraction limit optical spots were achievable. The spot size was 70% of the diffraction limit spot in design and no more than 80% in experiment. Furthermore, wavelength multiplexing subdiffraction limit optical spots can be generated in three dimensions. We applied the method to visual cryptography which was based on physical limit, and demonstrated that a secret image was visually recognized only by using a designated subdiffraction limit optical pattern as a key.

Free Research Field

情報フォトニクス