Design And Development Of Laser Dynamic Interference Processing System

The preparation of sub-micron surface structures is an effective way to realize various functional surfaces.Currently,commonly used preparation technologies mainly include mechanical processing,physical or chemical etching,laser etching,laser induced periodic surface structures,lithography,etc.However,all of these are difficult to achieve efficient and flexible preparation of sub-micron periodic surface structures.To solve this problem,a novel laser dynamic interference processing system has been developed in this research.Firstly,the design of laser dynamic interference processing system has been put forward,and its working principle has been analyzed.By designing the optical interference structure,the interference spot scanning based on the galvanometer control was realized.On this basis,the influence of the structure of the phase mask on the diffraction efficiency of±1st order diffracted laser beam was explored.The theoretical basis of the self-coupling characteristics during the overlapping of interference spots was studied.The influence of the laser polarization direction on the interference fringe contrast was analyzed.Secondly,combined with the analysis of geometric optics,the design parameters of the optical interference structure were determined.On this basis,the influence of the laser incidence angle of the phase mask on the quality of the interference spot was studied,which provided a reference for the design of the1)-telecentric field lens in the system.Thirdly,combined with numerical simulation,the system design was improved.By designing the1)-telecentric field lens,the perpendicularity between the scanning laser and the phase mask was ensured.By pre-shaping the laser,a focused interference spot with a good shape and size was obtained.At the same time,combined with the numerical simulation,the self-coupling characteristics during the overlapping of interference spots and the influence of laser polarization directions on the interference fringe contrast were proved.Finally,according to the design of the system,the experimental device was developed,and the effectiveness of the system design was verified.A 1064 nm picosecond laser was used to realize laser dynamic interference etching in 7×7 mm~2 on the surface of ITO conductive glass and specular 304 stainless steel.And one-dimensional or two-dimensional periodic structures with uniform profile were obtained.Various structural color patterns could also be obtained.The structure period was 760 nm.The etching efficiency of one-dimensional structures on the surface of two materials was greater than 16 mm~2/s and 8mm~2/s,respectively.The experimental research showed that the system could realize high-resolution selective processing,and had many advantages such as controllable,efficient,large area,low cost and pollution-free,which could be easily extended to the application research of various submicron periodic surface structures.