Prototype demonstration of the broadband anti-reflection coating on sapphire using a sub-wavelength structure

T. Matsumura, R. Takaku, S. Hanany, H. Imada, H. Ishino, N. Katayama, Y. Kobayashi, K. Komatsu, K. Konishi, M. Kuwata-Gonokami, S. Nakamura, H. Sakurai, Y. Sakurai, Q. Wen, K. Young, J. Yumoto