本研究利用光學薄膜理論設計並使用電子槍蒸鍍與離子源輔助蒸鍍系統鍍製方向聚集濾光片（angle-selective filters），應用在投光系統中改變其發光特性，其可提供良好的抗反射效果、選擇發光方向以及限制發光的角度，讓小角度的光源穿透，大角度的發光反射回光源以回饋再利用，使投光光源發光更具有方向性。
方向聚集濾光片設計為可控制斜向入射光源隨角度變化之穿透率，增強其光譜隨角度增加往短波偏移的效應，設計之濾光片往短波之偏移量為一般之短波通濾光片的2倍，以符合投光光源較為寬廣之光譜其設計之需求。
透過一系列濾光片隨入射角度增加光譜往短波偏移效應及隨入射角度增加光譜高反射區半高寬變化之分析，並針對投光光源設計及鍍製方向聚集濾光片，方向聚集濾光片可限制紅綠發光光源之出射角度在30°之內，抗反射之效果亦能增進投光光源發光之色彩表現。

We have designed and fabricated angle-selective filters to increase the luminous throughput of a light source system. The emission direction was tailored to increase the light emission in the useful direction by using multilayer optical coating with alternating high and low refractive indices layers.
Thin film filters can increase the effectiveness of the spectrum shifts toward shorter wavelengths with increasing the incident angle. The displacement of the designed filter is double that of the normal low pass filter so as to conform to the broad spectrum of light source.
The angle selective filters limit the luminance angle to less than an acceptance angle of 30 degrees for green and red light source. The filters increase the luminance efficiency by converging and recycling the light. And, the color performance of the light source was improved.

[1]J. J. Wierer, M. R. Krames, J. E. Epler, N. F. Gardner, and M. G. Craford, J. R. Wendt and J. A. Simmons, and M. M. Sigalas, “InGaN/GaN quantum-well heterostructure light-emitting diodes employing photonic crystal structures,” Appl. Phys. Lett., Vol. 84, No. 19, 3885-3887, 2004.
[2]K. McGroddy, A. David, E. Matioli, M. Iza, S. Nakamura, S. DenBaars, J. S. Speck, C. Weisbuch, and E. L. Hu, “Directional emission control and increased light extraction in GaN photonic crystal light emitting diodes,” Appl. Phys. Lett., 93, 103502-1~-3, 2008.
[3]XU Li, LI Yi , “Brightness enhancement method and apparatus of light emitting diodes ,” US Patent 036958 ,2008.
[4]Li Xu, Yi Li, “Multicolor illumination device using moving plate with wavelength conversion materials,” US Patent 7547114, 1998.
[5]C. C. Lee, “Thin Film Optics and Coating Technology, ” Yi Hsien Publishing Co., Ltd. Taipei, ISBN 957-616-884-8 （1999）.
[6]H. A, Macleod,“Thin-Film Optical Filters,” 2nded., Macmillan Publishing Company,N.Y.Adam Hilger Ltd, Bristol, 1986.
[7]R. R. Drenten, W. van Es-Spiekman, and C. J. van der Poel, “Semiconductor laser far-field shaping by means of an angle - selective facet coating,” APPLIED OPTICS, Vol. 30, No. 27, 0003-6935, 1991.
[8]Hongji Qi, Ruijin Hong, Kui Yi, Jianda Shao, and Zhengxiu Fan, “Nonpolarizing and polarizing filter design,” APPLIED OPTICS, Vol. 44, No. 12, pages 2343-2348, 2005.
[9]Xiaofeng Ma1, Dingquan Liu, Fengshan Zhang and Yixun Yan, “Non-polarizing broadband dichroic mirror,” OPTICS A PURE AND APPLIED OPTICS, VOL 9; NUMB 7, pages 573-576, 2007.
[10]W. B. Chen, P. F. Gu, ”Design of non-polarizing color splitting filters used for projection display system,” Displays 26, pp.65-70, 2005.
[11]Zheng Ping Wang, Jin Hui Shi, Shun Ling Ruan, ” Designs of infrared non-polarizing beam splitters,” Optics & Laser Technology 39, pp. 394–399, 2007.
[12]T. Ohtoshi, ”Effect of facet coatings on far fields of semiconductor
lasers,” Electron. Lett. 23, 570-571, 1987.
[13]S. Browning, D. Stephen, P. LeFebvre, et al, “Thin film dichroic color separation filters for color splitters in liquid crystal display systems,” US Patent 5,914,817, 1998.
[14]L. Epstein, “The design of optical filters,” J. Opt. Soc. Am. 42,806–810 (1952).
[15]Yang-Hua Chang, Chi-Chung Liu, Tzong-Jer Yang, and Chien-Jang Wu, ”Angular dependence of a narrowband reflection - and - transmission filter containing an ultrathin metallic film,” JOSA B, Vol. 26, Issue 5, pp. 1141-1145, 2009.
[16]Mitchell, Daniel Bruce , “Optical system with reflection - angle - selective mirror,” US Patent 7108383, 2006.
[17]http://www.luminus.com/content1130