Research And Application Of Narrow Beam Illumination Optical System Based On LD Excited Phosphor White Light Source

LED(Light Emitting Diode)has now become the mainstream lighting method,and it has many advantages that can meet almost all human expectations and requirements for artificial light sources.However,commercial white LEDs have the problem of "efficiency drop".When the applied current density increases,its light output efficiency will decrease rapidly.The laser diode has the characteristics of high brightness,high photoelectric efficiency and no "efficiency drop" phenomenon,long irradiation distance,simpler heat dissipation system,and small size.It has obvious advantages in the field of high brightness,high light efficiency,and remote lighting.As a technology that may replace LED lighting,laser lighting is of great significance for its research.This topic is based on the theory of illumination optics,non-imaging optics,etc.,the research of single LD(Laser diode)illumination optical system and array LD illumination optical system,and the characteristics of the fluorescent film used in laser illumination are simplified Research.The specific research content is as follows:1.Laser lighting is an emerging lighting method.Prior to the start of the project,we first carried out research and study on the principles of laser lighting,optical characteristics of laser diodes,characteristics of luminescent materials,non-imaging optical theory,etc.The research and application of laser illumination optical system will be a theoretical foundation2.Designed a single laser diode illumination optical system.In the optical simulation software LighTools,a trial and error method was used to design a cylindrical lens to achieve the first fast-axis beam shaping of the laser beam;a plano-convex lens was used to perform the second shaping of the laser beam;a narrow beam was designed to achieve the narrow beam exit of the white light spot Straight lens.The phosphor model is established,and the laser beam excites the phosphor to obtain white light.Due to the poor effect,the optical system was optimized and improved by adding an aperture Finally,it is concluded that when the fluorescent film is 18.8mm away from the laser diode light exit surface and the aperture is 1mm,the light intensity is 51952cd,and the beam angle is 1.69°.When the fluorescent plate is 22mm away from the laser diode light exit surface and the aperture of the diaphragm is lmm,the light intensity is 67560cd and the beam angle is 1.53°.It can be seen that the narrow beam exit of the light source is realized.And design the mechanical model of each module and assemble the light source module in 3D modeling software.Process the designed light source module and build an experimental system to verify it3.Innovative design of array laser illumination optical system.In order to achieve collimation of the laser beam,based on the Monte Carlo ray tracing theory,the principle of edge ray and the vector form of Snell's law and the characteristics of the laser beam,the simultaneous design of multiple surfaces is carried out.After calculating the discrete points using MatLab,the 3D model of the lens is generated by the 3D modeling software,and a double freeform collimating lens is obtained to control the collimation of the laser beam,and its effectiveness is analyzed.Using TracePro to simulate and trace Monte Carlo rays of the optical system has achieved a laser diode light collection rate of 98.4%.In TracePro and 3D modeling software,the reflector cup and the substrate model carrying LD are designed to converge the array LD laser beam.The designed uniform light system utilizes the light mixing effect of the light guide column to perform secondary optical shaping of the laser beam to achieve laser beam expansion and homogenization.The designed laser beam secondary shaping system improves the unevenness of the laser spot from 11.1%to 1.7%after optimization;and the light guide column used in this design can fully disrupt the laser beam and achieve a good beam spreading and uniform light effect.Can be used as a high-quality light source to excite the fluorescent film4.Designed the fluorescent film and studied the influence of the characteristics of the fluorescent film on the white light spot formed.It is concluded that a thickness of 0.8 mm and a concentration of 10.96 mol/liter are the preferred properties parameters of the fluorescent sheet.The uniformity of the light spot and the angle of the beam after collimated by the collimating lens were analyzed,and the addition of the diaphragm and the matte surface on the light exit surface was optimized to obtain a narrow beam square with 98%illumination uniformity and beam angle of 1.6° Light spot.It makes the components of the array LD lighting module get the best integration,and finally designs and implements an array narrow beam laser lighting optical system.