Fig. 1. Sketch diagram of femtosecond laser processing system.

Fig. 2. SEM images of stripe structures induced by different laser powers: (a) 2.50 μW, (b) 2.76 μW, (c) 2.92 μW, and (d) 3.07 μW; insets are the Fourier transform spectrum patterns corresponding to the stripes processed with different laser powers.

Fig. 3. Two-cycle nano composite structures induced by different scanning directions and laser polarization directions: (a1) the scanning direction is the same as the polarization direction, (b1) the direction of scanning is perpendicular to the polarization direction, (c1) the angle between the directions of scanning and polarization is 45°; (a2)–(c2) are the corresponding magnification images of (a1)–(c1).

Fig. 4. Surface enhanced Raman scattering (SERS) measurements of the diamond surface nano-stripe structure: (a) the R6G molecules of 10−5mol/L were used as probes, and thicknesses of 0 nm, 13 nm, 22 nm, 30 nm, 38 nm, 47 nm, and 55 nm gold films were sputtered on the nano-stripes; (b) R6G molecules with different concentrations with 47-nm-thick gold film on nano-stripe structure.

Fig. 5. Control of the induced stripe direction in the scanning tracks by changing the polarization direction of the laser: (a) the scanning direction is the same as the polarization direction, (b) the direction of scanning is perpendicular to the direction of polarization, (c) the angle between the direction of scanning and the direction of polarization is 45°, and (d) the direction of polarization changes 90°, (e) the direction of polarization changes 180°, and (f) the direction of polarization changes 360°.

Fig. 6. Circular micro-nano composite structures were prepared when the laser scanning path and the polarization direction were changing at the same time: (a1), (a2) fixed polarization direction; (b1), (b2), (c1), (c2) change of polarization direction from the initial phase of 2π; (d1), (d2) change of polarization direction from the initial phase of 4π; (e1), (e2) change of polarization direction from the initial phase of 6π.