本研究提出新方法模擬雙螢光粉白光LED模型並進行實驗驗證。此方法是利用近場色彩光學實驗資料與光學模擬軟體LightTools搭配，找出在LightTools中的關鍵參數，精準的預測雙螢光粉白光LED特性。
因為此研究的白光LED為雙螢光粉，在建構螢光粉模型時，兩種螢光粉之間會有許多的參數交互作用，造成模擬軟體的過度負擔，以及增加光學工程師建構模型時間。為了解決此問題，本研究提出將螢光粉分成兩種獨立特性，第一種為吸收與轉換光線特性，第二種為散色特性，並用平均自由路徑 (MFP)取代螢光粉濃度參數及螢光粉顆粒大小。雖然這是一個等效的螢光粉模型，但它可以快速的建構及精準的預測雙螢光粉白光LED的特性。例如: 本方法可以預測，在近場中LED的色彩與亮度會隨著LED發光表面位置不同，而有不同的光學特性。
根據此研究方法，也可以精準的預測各種LED設備光學特性，例如:鑲嵌在silicone的LED、表面鍍膜的LED。

An innovative way of dual phosphors-converted white LED modeling is established and demonstrated. We use near-field chromatic luminance measurement data to investigate the effect of modeling parameters in Lighttools and propose some key parameters to predict characteristics of LEDs accurately. Because of dual phosphors LEDs, there are many varied parameters to affect results of simulation. It is not only overloading in Lightools but also inefficient. In order to decrease interaction of each parameter, there is an efficient method to be provided as well. The novel thing is that we use mean free path (MFP) to replace a concentration and particle size of phosphors without scattering and add Mie particle to describe scattering of phosphors specifically. It’s an equivalent phosphors model which can predict characteristic of dual phosphors-converted LEDs very well. For example, there is a strong dependence of the luminance and the color as a function of position on the LED surface of a phosphor-converted medium-power LED. Our method can accurately predict this phenomenon. Based on our model, we successfully predict characteristics of embedding LEDs in optical devices and coating LEDs with special materials.

[1] Borbely, A. and Johnson, S., “Performance of phosphor-coated light-emitting diode optics in ray-trace simulations,” Opt. Engineering, 111308-1 – 111308-4 (2005).
[2] Hung, C. H. and Tien, C. H., “Phosphor-converted LED modeling by bidirectional photometric data,” Opt. Express 18, A261–A271 (2010).
[3] Sun, C. C., Lee, T. X., Ma, S. H., Lee, Y. L., and Huan, S. M., “Precise optical modeling for LED lighting verified by cross correlation in the midfield region,” Opt. Letters 31, 2193–2195 (2006).
[4] Moreno, I. and Sun, C. C., “Modeling the radiation pattern of LEDs,” Opt. Express 16, 1808–1819 (2008).
[5] Chien, W. T., Sun, C. C., and Moreno I., “Precise optical model of multi-chip white LEDs,” Opt. Express 15, 7572–7577 (2007).
[6] Hsiao, S. L., Hu, N. C. and Cornelissen, H. J., “Phosphor-converted LED modeling using near-field chromatic luminance data,” Opt. Express 21, A250-261, (2013).
[7] You, J. P., Tran, N. T. and Shi, F. G., “Light extraction enhanced white light-emitting diodes with multi-layered phosphor configuration,” Opt. Express 18, 5055–50560 (2010).
[8] Zollers, M., “Phosphor Modeling in LightTools,” Synopsys, (2011)
[9] Radian Zemax company, https://www.radiantzemax.com/
[10] Nichia Company, http://www.nichia.co.jp/
[11] SPIE
[12] http://www.eneltec-led.com/LED-Lighting-Blog/how-to-make-high-quality-led-chips-2/
[13] http://cn.dreamstime.com/%E5%BA%93%E5%AD%98%E7%85%A7%E7%89%87-%E7%94%B5%E7%A3%81%E6%B3%A2%E9%A2%91%E8%B0%B1-image31930793