Yeuh-Yeong LIOU^*, Zhi-Wei WEI, Li-Rang WANG, Chi-Chang LIU¹, Chin-Chiuan KUO¹, Cheng-Chung JAING², and Cheng-Chung LEE³

Department of Electronic Engineering, Chienkuo Technology University, No. 1, Jieh Shou N. Rd., Chang-Hua 500, Taiwan, R.O.C.
¹Mechanical Engineering and Graduate Institute Manufacturing Technology, Chienkuo Technology of University, No. 1, Jieh Shou N. Rd., Chang-Hua 500, Taiwan, R.O.C.
²Department of Optoelectronic System Engineering, Minghsin University of Science and Technology, No. 1, Hsin-Hsing Rd., Hsin-Fong, Hsin-Chu 304, Taiwan, R.O.C.
³Department of Optics and Photonics, National Central University, No. 300, Jhongda Rd., Jhongli City, Taoyuan County 320, Taiwan, R.O.C.

(Received July 10, 2008; Accepted December 5, 2008)

A spiraling search method is applied to design a wide angular visible antireflection (AR) coating with an incident angle of up to 50^° above normal. Only a two-material multilayer system with high- and low-index is used in the design. It is shown that the maximum visible reflectivity can be reduced to below 1.26%, and that the total average wide-angle visible spectral reflectivity can be reduced to lower than 0.33%, respectively. Not only is the wide-angle visible AR performance in the designed range very acceptable, but it is found that the visible reflectivity for that incident angle beyond 50^° can also be decreased.

Key words: antireflection coating, wide angular, broadband, spiraling search, design algorithm

^*E-mail address: yyliou@ctu.edu.tw