Fig. 1. Schematic of simulated structure of “moth’s eye”

Fig. 2. Schematic of inverted cone-shaped simulated structure

Fig. 3. Raman spectrum and transmittance analysis of diamond. (a) Change of optical transmittance of CVD diamond with laser irradiation times at different energy densities (τ=220 ps, λ=539 nm)^[46]; (b) Raman spectrum of laser processed diamond^[48]

Fig. 4. Construction of diamond micro-nano structure and simulation results of transmittance^[3]. (a) Diagram of diamond surface micro-nano structure; (b) calculated wavelength dependence of theoretical transmittance of untreated diamond surface and diamond surface treated by LIPSS technology with different polarization

Fig. 5. Evolution of diamond surface morphology with the increase of pulse time delay^[59]

Fig. 6. SEM images of diamond subwavelength grating and transmittance curves before and after grating construction^[74]. (a)-(b) A micro-nano structure designed to reduce periodicity of surface reflection grating at 10.6 μm; (c) variation of diamond transmittance with wavelength

Fig. 7. Effect of diamond structure on transmittance^[76]. (a) Transmission spectrum of diamond after etching SWG; (b) transmission spectra at different depths

Fig. 8. Broad-band anti-reflection “pyramid” structure on diamond surface^[77]. (a) SEM micrograph of etched structure; (b) variation of transmittance with wavelength; (c) simulation diagram of “pyramid” structure

Fig. 9. Micro-nano structure and transmittance change of diamond^[19]. (a) Schematic of diamond micro-nano structure; (b) transmittance curves of diamond with and without micro-nano structure, and simulated transmittance curve