基于光学薄膜的LED光谱调制技术

针对白光LED光谱与自然光谱的不同,讨论了采用光学薄膜改善白光LED光谱的可行性,同时提出了一种利用光学薄膜消除白光LED发光光谱中蓝光成份的方法,设计了光学薄膜的透过率曲线,并分析了其可行性.针对单色LED光谱随温度不同发生变化的特点,根据分析样品在4.9°、24°和49°三种环境温度下的光谱分布,设计了一种光学薄膜的透过率曲线,分析利用该设计薄膜改善单色LED光谱温度稳定性的可行性及结果.研究结果表明,在保证白光LED出光效率的前提下,仅靠在发光芯片上镀制光学薄膜的方式并不能改善光谱的结构,而使之与自然光中的可见光谱相似.采用设计的光学薄膜,可以消除白光LED发光光谱中的蓝光波段,提高光谱的舒适性.在4.9°、24°和49°三种环境温度下,利用设计的薄膜可将分析LED的发光光谱的中心波长稳定在700 nm附近,相对发光强度稳定在0.2附近,不同温度时光谱分布的相似性也有了较大的改善,研究结果有助于LED照明光源的进一步应用.

LED Spectrum Modulation Technique Based on Optical Coating

According to the differences between the white LED spectrum and the visible light spectrum, the feasibility of using optical coating to improve the spectrum is discussed. Meanwhile, a novel method is proposed to eliminate blue band of the white LED spectrum. The transmittance of the required optical coating is calculated, and the feasibility of method is analyzed. According to the spectrum of the single LED is different at the different temperatures, the transmittance of the required optical coating is calculated based on the spectrum of the single LED at the temperature 4.9?, 24?, 49?, and the feasibility of using optical coating to improve the temperature stability of the single LED spectrum is analyzed. The results show that the method of using optical film coated on the LED chip does not improve the structure of the white LED to make it similar with the visible light spectrum. The blue band of the white LED spectrum can be eliminated and improve the comfort of the spectrum using the designed optical thin film. The center wavelength and the relative luminous of the analyzed single LED can be stabilized at the 700 nm and 0.2 at the temperature 4.9?, 24?, 49? using the designed optical film. The similarity of the spectrum at the different temperature is improved greatly. The results contribute to the further application of LEDs.