 Masato Shibuya, Masato Shibuya, Kazuhisa Maehara, Kazuhisa Maehara, Yoshihito Ishikawa, Yoshihito Ishikawa, Akira Takada, Akira Takada, Kei Kobayashi, Kei Kobayashi, Mitsunori Toyoda, Mitsunori Toyoda, Masanori Tanikawa, Masanori Tanikawa, Suezou Nakadate, Suezou Nakadate, Theoretical investigation of the meaning of odd-order aspherical surface and numerical confirmation of effectiveness in rotational-symmetric but off-axis optics, Optical Engineering 497, 073003 1 July 2010. . Submission: 