title: Improving LED CCT uniformity using micropatterned films optimized by combining ray tracing and FDTD methods.
abstract: Although the light-emitting diode (LED) has revolutionized lighting, the non-uniformity of its correlated color temperature (CCT) still remains a major concern. In this context, to improve the light distribution performance of remote phosphor LED lamps, we employ a micropatterned array (MPA) optical film fabricated using a low-cost molding process. The parameters of the MPA, including different installation configurations, positioning, and diameters, are optimized by combining the finite-difference time-domain and ray-tracing methods. Results show that the sample with the upward-facing convex-cone MPA film that has a diameter of half of that of the remote phosphor glass, and is tightly affixed to the inward surface of the remote phosphor glass renders a superior light distribution performance. When compared with the case in which no MPA film is used, the deviation of the CCT distribution decreases from 1033 K to 223 K, and the corresponding output power of the sample is an acceptable level of 85.6%. We perform experiments to verify our simulation results, and the two sets of results exhibit a close agreement. We believe that our approach can be used to optimize MPA films for various lighting applications.
authors.forename: Xinrui
authors.initials: X
authors.lastname: Ding
authors.forename: Jiasheng
authors.initials: J
authors.lastname: Li
authors.forename: Qiu
authors.initials: Q
authors.lastname: Chen
authors.forename: Yong
authors.initials: Y
authors.lastname: Tang
authors.forename: Zongtao
authors.initials: Z
authors.lastname: Li
authors.forename: Binhai
authors.initials: B
authors.lastname: Yu