Fig. 1. Structural diagram of LD end-pumped solid-state laser

Fig. 2. Schematic diagram of pump light shaping structure

Fig. 3. Zemax simulation diagrams of pump light shaping.

Fig. 4. Output intensity distributions of pump light after shaping. (a) At focal point; (b) at 7 mm position behind focal point

Fig. 5. Dual-pass amplified output pulse energy versus peak power of pump light

Fig. 6. Intensity distribution of seed light and optical properties of amplified light. (a) Seed light intensity distribution at Nd∶YVO₄ laser crystal; (b) near-field spot after dual-pass amplification; (c) pulse waveform after dual-pass amplification; (d) beam quality after dual-pass amplification

Fig. 7. Optical characteristics of output 355 nm ultraviolet laser . (a) Energy; (b) pulse waveform; (c) beam quality factor; (d) wavelength

Fig. 8. Mechanical structure of laser

Fig. 9. Comparison between designed scheme and pump LD with pigtail output