In order to improve the heat dissipation of LED, Snell's law and principle of energy conservation are adopted. By applying the equal relationship between the light vectors, a mathematical model of the collimation free-form TIR lens is established. In order to reduce the heat dissipation, the TIR transmission surface is studied. Niel surface design. In order to improve the illuminance of the target, a 9×9 array design was performed on the designed Fresnel lens using Sparrow's rule. Optical simulation using lightools. When the light source array is 10m away from the target surface. The uniformity of light on the target surface not only satisfies 0.7, but the heat dissipation effect has also been significantly improved.
Laser afocal zoom expander system due to the beam diameter variable, can be used in the light sheet illumination microscope to observe the samples of different sizes. Based on the principle of afocal zoom system, the laser collimation and beam expander system with a total length of less than 110mm, 6 pieces of spherical lens and a beam expander ratio of 10 is designed by using Zemax software. The system is focused on laser with a wavelength of 532nm, divergence angle of less than 4mrad and incident diameter of 4mm. With the combination of 6 spherical lens, the beam divergence angle is 0.4mrad at the maximum magnification ratio, and the RMS values at different rates are less than λ/4. This design is simple in structure and easy to process and adjust. It has certain practical value.