Fig. 1. Device diagram of ultraviolet nanosecond laser processing of CVD diamond

Fig. 2. SEM images of diamond microgroove. (a) Overall view of microgroove; (b) surface of microgroove; (c) entrance of microgroove；(d) sidewall of microgroove

Fig. 3. Raman spectra at each position of diamond microgroove. (a) Surface topographies of microgrooves at different positions; (b) Raman spectra at different positions

Fig. 4. SEM morphologies of diamond microgrooves processed with different pulse energies. (a)(c) Top views; (d)(f)side views

Fig. 5. Effects of laser pulse energy on size of microgroove. (a) Depth and width of microgroove versus pulse energy; (b) S of microgroove versus pulse energy

Fig. 6. Side views of optical images of diamond microgrooves processed at different scanning speeds

Fig. 7. Effects of scanning speed on size of microgroove. (a) Depth and width of microgroove versus scanning speed; (b) S of microgroove versus scanning speed

Fig. 8. Side views of optical images of microgrooves processed with different numbers of scannings

Fig. 9. Effects of number of scannings on size of microgroove. (a) Depth and width of microgroove versus number of scannings; (b) S of microgroove versus number of scannings

Fig. 10. Side views of optical images of microgrooves processed with different repetition frequencies

Fig. 11. Effects of repetition frequency on size of microgroove. (a) Depth and width of microgroove versus repetition frequency; (b) S of microgroove versus repetition frequency

Fig. 12. Side views of optical images of diamond microgrooves processed with different defocus distances

Fig. 13. Effects of defocus distance on size of microgroove. (a) Depth and width of microgroove versus defocus distance; (b) S of microgroove versus defocus distance

Fig. 14. Diamond microgrooves machined with optimized processing parameters.(a)Top view of microgrooves; (b)cross-sectional view of microgrooves at edge of diamond；(c)enlarged view of bottom of microgroove at edge of diamond; (d)cross-sectional view of microgrooves in middle part of diamond