Fig. 1. Schematic diagram of the micropattern preparation. (a) Process flow diagram; (b) schematic diagram of the laser writing system

Fig. 2. Characteristics of single-layer micropattern. (a) Transmittances of glass substrate and micro pattern; (b) principle of multilayer imaging

Fig. 3. SEM image of the micropattern

Fig. 4. Imaging results of the optical microscope. (a) Multilayer micropatterns; (b) resolution plate images under glass substrates with different layers

Fig. 5. Simulation results of the light field. (a) Influence of crosstalk on the model; (b) field distribution after plane wave incident; (c) field distribution after random light field incident

Fig. 6. MTF of the system under glass of different thicknesses. (a) D=0.34 mm; (b) D=3.4 mm; (c) D=6.8 mm (single layer); (d) D=6.8 mm (multilayer)

Fig. 7. Signal diagram under different layers. (a) Interception position of the light intensity signal; (b) signal diagrams at different layers

Fig. 8. Different paths in the back and forth reflection and the offset distance of the object plane

Fig. 9. Simulation diagram of the reflected field light intensity. (a) Distribution of the reflected field on the object surface; (b) distribution of the light field after passing through all the interfaces

Fig. 10. Bottom layer imaging results of different filling media. (a) Air; (b) ethanol

Fig. 11. Contrast of different images. (a) Original image; (b) processed image