Fig. 1. Optical schematic of experimental setup

Fig. 2. Photon conversion efficiency of the first Stokes (S1) Raman laser under different deuterium gas pressures and pulse energies (peak power) of pump light. (a) Deuterium gas pressure of 0.51.5 MPa; (b) deuterium gas pressure of 2.03.5 MPa; (c) comparison of photon conversion efficiency curves between double focus with deuterium gas pressure of 3 MPa and single focus with focal length of 1500 mm

Fig. 3. Spectrum and pulse waveform of S1 Raman laser. (a) Spectrum of S1 laser; (b) pulse waveform of S1 laser

Fig. 4. Numerical simulation curve of the change for SRS overall gain coefficient G versus translation distance of focusing lens

Fig. 5. Maximum photon conversion efficiency of S1 vs. position of L1 under different deuterium gas pressures

Fig. 6. S1 photon conversion efficiency and pulse energy vs. pulse energy of pump laser in the condition of 3 MPa deuterium gas pressure and the focusing lens L1 moves 36 cm towards the entrance of the Raman cell (23 cm from the entrance of the Raman cell)

Fig. 7. Pulse energy of S1 laser and photon conversion efficiency vs. pulse energy of pump laser in the long path cell configuration

Fig. 8. Experimental setup of second-harmonic generation (SHG)

Fig. 9. Conversion efficiency and pulse energy of 780 nm laser produced by 1560 nm laser second harmonic generation

Fig. 10. Beam quality of 780 nm laser