在本論文中，為了探討矽酸鹽螢光粉於白光LED封裝之光學特性，我們建立了螢光粉光學模型，其中結合米氏散射原理及蒙地卡羅光追跡法來分析光於螢光粉膠體中傳遞時所造成的體散射效應，並藉由藍光與黃光兩次光追跡法來描述白光LED之光學行為。最後，經由實驗與模擬之驗證與分析，我們成功地建立矽酸鹽螢光粉的光學模型，可運用於設計白光LED之封裝形式，避免空間色分佈不均勻的現象。但由於矽酸鹽螢光粉的光學特性，如:螢光粉再吸收和螢光粉熱衰現象，使我們的模型尚存在有許多的限制條件，需要更多的實驗數據來修正模型。

In this thesis, we study the optical model to precisely describe optics and color distribution of the lights emitted by a blue LED covered with silicate phosphors. The optical model starts Mie scattering model and Monte Carlo ray tracing to describe the scattering of the lights when they are propagated in the phosphors, and the ray tracing is performed with blue and yellow rays. Through simulation and experimental measurement, we have successfully built an optical model, which can be applied to decide some package parameters in a white LED and to avoid color dispersion of the light pattern. Besides, we observed some interesting effects such as thermal decay and re-absorption of the phosphors. These effects could limit the validity of the optical model and need more study to make the optical model more correct.

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