Toshimitsu TAKAOKA^1*, Naoki KAWANO^1†, Yasuhiro AWATSUJI^1,2‡ and Toshihiro KUBOTA¹

¹Department of Electronics and Information Science, Faculty of Engineering and Design, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
²PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan

(Received September 24, 2004; Accepted December 12, 2005)

A compact beam-shaping device with a reflective aspherical surface is proposed. The device converts a circular symmetric Gaussian beam from a laser into a uniform distribution on a target plane. The device consists of a laser, a reflective aspherical surface formed on the base plane inclined by 45° against the optical axis, and a spacer. The surface is designed for an optical device used as a transmitter of indoor wireless optical communication, which is one of the promising applications. The designed surface is obtained by approximation using polynomial. Beam shaping of a simulated surface and a uniform intensity distribution on the target plane is obtained. The intensity distribution generated by the surface is numerically simulated and evaluated if the surface is misaligned. It is clarified that the generated distribution is tolerable for the misalignment.

Key words: optics design, beam shaping, optical device, aspherical surface, uniform illumination, beam homogenizer

^*Present address: Nalux Co., Ltd.
^†Present address: Ushio Inc.
^‡E-mail address: awatsuji@dj.kit.ac.jp