Study On Photoluminescence Characteristics Of High Brightness Solid-state Green Light Source

The HLD light source in the projection not only has the advantages of green solidstate light source,environmental protection and long life,but also has the advantages of high brightness that solid-state LED lacks and low cost that direct laser light source lacks.It is the key to have the high brightness solid-state light source in the field of projection.Today,the technology of high brightness green light using blue-light excited fluorescent crystal can break through the limitation of optical expansion and become one of direction of high brightness green light source.However,the green light source using excited fluorescent crystal lacks the corresponding luminescence model,the excitation mode is rough,and the brightness has a larger room for improvement.The brightness is affected by optical expansion,which is determined by the light transmission inside the fluorescent crystal.Exploring the relationship between light transmission and optical expansion of fluorescent crystals is very important to enhance the brightness of light sources.Through theoretical analysis of light transmission of green light source,the paper explores the relationship between blue light excitation mode and optical expansion,hoping to optimize the excitation structure of green light source,and then achieve a significant increase in luminance of green light source.In this paper,starting from the mechanism of blue-green light conversion transmission,exploring the photoluminescence mechanism of fluorescent materials,studing the transmission of light in fluorescent crystals,and establishing the physical model of fluorescent crystals when stimulated.Specific research contents are as follows:Establishment of blue-green conversion and light transmission models for fluorescent crystal materials.The illumination loss of HLD source is described by parameters of etendue,which calculated with far-field spatial distribution and near-field spatial distribution of HLD source.In addition,these parameters are related to the internal light transmission when the fluorescence crystal is stimulated.And the far-field spatial distribution and near-field surface distribution of fluorescent crystals can be simulated by the light transmission model of fluorescent crystal materials.Exploring the analytical method of etendue in photoluminescence green light source.The light transmission model can simulate near-field distribution and far-distribution quickly in different excitation ways.The parameters of different excitation ways of the thickness of fluorescence crystal,the beam,the angle of incidence,the depth of focus,the angle of inclination and the shape of the sample.The simulation correctness of far-field spatial distribution and near-field surface distribution are verified by the experimental measurement.The simulation theory needs to be verified by experiments.The simulation and experiment results of near-field distribution and far-field surface distribution has the same parameters.It is verified that the theory of light transmission model is basically with actual situation of fluorescent crystal.The above works explores the possibility of fluorescent crystal as a conversion material in HLD source.The experimental results show that the fluorescent crystal is very suitable for fluorescent conversion material in HLD source.The light transmission model can simulate the near-field surface distribution and far-field spatial distribution conveniently.So,the excitation structure can be optimized by light transmission model.The methods can improve the energy utilization of the HLD source,while reducing the cost and smaller the volume.