Optical Design And Measurement Of White-LED's Phosphor Layer

Mixed with phosphor layer's yellow light emitted by the incident blue light which is emitted from GaN diode, blue light from White-LED's chip turn white. Now White-LED is a hot-spot of research. The point of designing White-LED used for lighting is its color temperature and efficiency. And White-LED's phosphor layer is very important to this. Not only White-LED's efficiency, but also its color and light distribution will be affected by changing phosphor's granularity, thickness and size.The first and second chapter introduces the basic theory of White-LED and Monte Carlo Methods, analyzing the importance and possibility of designing White-LED's phosphor layer. In the third chapter, writer analyzed the process of photon's transportation and changing in White-LED's phosphor layer. After that, writer programmed the simulation programme.In order to prove the mode, writer designed a simulation experiment of phosphor layer in chapter five. To measure the samples' scattering coefficient and absorption coefficient with different sick and density, writer proposed a method called double wavelength transmission measurement. By comparing the result of simulation and double wavelength transmission measurement, writer proved the mode. In the forth chapter, writer calibrated the spectrometer which was used in the experiment.At last, writer analyzed the affection of phosphor layer's absorption coefficient and scattering coefficient by using the simulation progamme. He concluded a few regularity in designing White-LED's phosphor layer and proposed a flow process chart of designing White-LED's phosphor layer.