Study On Micro - Grating Micro - Lens Prepared By Femtosecond Laser

With the development of nanotechnology, micro-optics devices are widely applied in communication, data storage, imaging and sensing. Micro- grating and micro- len array are hot spot in micro-optics device research. Therefore, how to manufacture the micro-lens array and micro-grating more efficiently is becoming the urgent requirement.The femtosecond laser is a kind of ultra-short pulse laser with high peak power and small scope. It has become one of the best micro processes. It can realize non-hot melt processing. After processing procedure, its surface is very smooth. Therefore, it has become one of methods of processing micro-grating and micro-lens.In this thesis,the laser direct writing system which is built by femtosecond laser and micro-displacement platform is used to process micro grating on polycarbonate surface. The relationship between processing line width of polycarbonate surface and laser energy is studied. At the same time, the influence of microscope objective which has different numerical apertures on the processing line width is studied.A two-beam interferometry processing system was built up. The incident light beam is split by Ronchi grating. Through controlling the exposure time, many sets of grating structures are processed on the polycarbonate surface. The influence of the laser pulse on the morphology of the grating is studied.The above direct writing system is used to ablation micro-pores on polycarbonate and polymethylmethacrylate surface. Then, the ablation effect of two mate rials is compared. The influence of laser parameter on micro-pore diameter is studied. Finally, polycarbonate material is selected to manufacture a large number of micro concave lens arrays. The imaging performance of micro concave lens array is tested.