Fig. 1. Distribution of four circular holes in the mask and its Fourier spatial spectrum. (a) A mask; (b) Fourier spatial spectrum of the mask

Fig. 2. Processing equipment and results.(a) CO₂ laser processing diagram for processing lattice structure(enlarged image for mask); (b) 3×3 lattice structure prepared on fused silica substrate (microscope picture, the picture in the upper right corner is an enlarged view of a single structure); (c) 5×5 lattice structure prepared on the cover slip substrate (microscope picture)

Fig. 3. One-dimensional depth distribution of structure.(a) One-dimensional depth distribution of three structural points in the center of the lattice; (b) one-dimensional depth distribution of two structural points above the center of the lattice; (c) one-dimensional depth distribution of the top single structural point

Fig. 4. FP microcavity assembly and laser testing. (a) Assembly of FP microcavity; (b) optofluidic laser test device; (c) far field image of laser emission collected by CCD; (d) laser spectrum