[1] [1] Wang P P, Yang X B, Zhu J F, Xiong D X. Design and analysis on large area uniform illumination with fly-eye lens. Journal of Applied Optics, 2014, 35(5): 771-778

[2] [2] Kuang L J. Characteristics of fly-eye lens in uniform illumination system. Optics & Optoelectronic Technology, 2005, 3(6): 29-31

[3] [3] Lee X H, Moreno I, Sun C C. High-performance LED street lighting using microlens arrays. Optics Express, 2013, 21(9): 10612-10621

[4] [4] Wang G, Wang L, Li F, Kong D. Design of optical element combining Fresnel lens with microlens array for uniform lightemitting diode lighting. Journal of the Optical Society of America A, Optics, Image Science, and Vision, 2012, 29(9): 1877-1884

[5] [5] Whang A J W, Chen Y Y, Teng Y T. Designing uniform illumination systems by surface-tailored lens and configurations of LED arrays. Journal of Display Technology, 2009, 5(3): 94-103

[6] [6] Domhardt A, Rohlfing U, Lemmer U. TIR optics for nonrotationally symmetric illumination design. In: Proceedings of Illumination Optics, Glasgow. SPIE, 2008, 710304

[7] [7] Ma D L, Feng Z X, Liang R G. Freeform illumination lens design using composite ray mapping. Applied Optics, 2015, 54(3): 498- 503

[8] [8] Bao Z C, Zhu J, Xiong S S, Jin G F. The design of freeform surface lens for LED lighting system. In: Proceedings of International Symposium on Photoelectronic Detection and Imaging, Beijing. SPIE, 2013, 89130T

[9] [9] ing Y, Liu X, Zheng Z R, Gu P F. Freeform LED lens for uniform illumination. Optics Express, 2008, 16(17): 12958-12966

[10] [10] Qiao Q F, Lin F. Freeform surface secondary lens for LED streetlight. Journal of Applied Optics, 2012, 33(4): 675-679

[11] [11] Zhenrong Z, Xiang H, Xu L. Freeform surface lens for LED uniform illumination. Applied Optics, 2009, 48(35): 6627-6634

[12] [12] Luo Y, Feng Z, Han Y, Li H. Design of compact and smooth freeform optical system with uniform illuminance for LED source. Optics Express, 2010, 18(9): 9055-9063

[13] [13] Wang K, Chen F, Liu Z, Luo X, Liu S. Design of compact freeform lens for application specific light-emitting diode packaging. Optics Express, 2010, 18(2): 413-425

[14] [14] Feng Z, Luo Y, Han Y. Design of LED freeform optical system for road lighting with high luminance/illuminance ratio. Optics Express, 2010, 18(21): 22020-22031

[15] [15] Situ W, Han Y, Li H, Luo Y. Combined feedback method for designing a free-form optical system with complicated illumination patterns for an extended LED source. Optics Express, 2011, 19 (Suppl 5): A1022-A1030

[16] [16] Wang S, Wang K, Chen F, Liu S. Design of primary optics for LED chip array in road lighting application. Optics Express, 2011, 19 (Suppl 4): A716-A724

[17] [17] Hu R, Luo X, Zheng H, Qin Z, Gan Z, Wu B, Liu S. Design of a novel freeform lens for LED uniform illumination and conformal phosphor coating. Optics Express, 2012, 20(13): 13727-13737

[18] [18] Hu R, Gan Z Q, Luo X B, Zheng H, Liu S. Design of double freeform-surface lens for LED uniform illumination with minimum Fresnel losses. Optik (Stuttgart), 2013, 124(19): 3895-3897

[19] [19] Chen J J, Huang Z Y, Liu T S, Tsai M D, Huang K L. Freeform lens design for light-emitting diode uniform illumination by using a method of source-target luminous intensity mapping. Applied Optics, 2015, 54(28): E146-E152