Takehito OONISHI^*, Tsuyoshi KONISHI, and Kazuyoshi ITOH

Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan

(Received January 31, 2007; Accepted July 2, 2007)

A binary subwavelength structure for multilevel phase modulation can be designed by our previously proposed deterministic design method without iterative optimization method. To use our design technique in various applications of a computer generated hologram (CGH) like an array illuminator, beam-shaping, signal processing, and so on, an image quality of a reconstructed image from a CGH has become much more important. In this paper, we verify the image quality of a reconstructed image from a CGH designed by our method in terms of the modulation transfer function (MTF) and the spatial resolution. Simulation results show that our technique can theoretically achieve a MTF of more than 99% over a wide range and a spatial resolution of less than 9.66 μm.

Key words: subwavelength structure, SWS, computer generated hologram, CGH, diffractive optical element, effective refractive index, FDTD method, modulation transfer function, MTF

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