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UEC Int’l Mini-Conference No.52 71

Electron Beam Fabrication of Phase Hologram

Tonmoy Hasan CHOWDHURY , Yoko MIYAMOTO
*
* Department of Engineering Science, the University of Electro-Communications
* Institute for Advanced Science, the University of Electro-Communications
1-5-1 Chofugaoka, Chofu, Tokyo, 182-8585, Japan

Keywords: Electron beam fabrication, optical vortex array, phase hologram, classical and quantum information
communication.

Abstract

A hologram is an optical element that modifies incident light's phase and/or amplitude distributions. Electron beam
fabrication of holograms is a process where the electrons can be finely focused and dosed on polymer layers on
glass substrates to create holographic patterns with submicrometer precision. In this research, we used electron
beam exposure to fabricate a 10,000 x 10,000 pixels phase hologram in a 2 mm square area with a pixel size of
200nm. To create the desired pattern, we designed the pattern with MATLAB and put the pattern into electron
beam exposure. To create the polymer layer, we coated a glass substrate with transparent conducting material
(indium-tin-oxide), then spin-coated with electron-beam resist polymer (gL1000-5) and baked at 180℃ for 3
minutes to make the coating persistent, the electrons were then dosed to write the pattern on the polymer. The
phase hologram is designed with a blazed structure to concentrate power in the 0th and 1st diffraction orders when
used as a reflection grating. We realized the optical vortex array with orders up to ±3rd for phase holograms. The
generated optical vortex array can be used for classical and quantum information communication by developing a
multiplexing-demultiplexing system.

*The author is supported by (AiQuSci) MEXT scholarship.