Fig. 1. Pr∶LiYF₄ crystal

Fig. 2. Pr∶LaF₃ crystals with different doping concentrations of Pr³⁺. (a) 0.5%; (b) 1%

Fig. 3. Band structure, partial density of states, and polarized absorption spectrum of face-contact Ti³⁺-Ti⁴⁺ ion pair model^[93]

Fig. 4. Band structure and polarized absorption spectrum of line-contact Ti³⁺-Ti³⁺ ion pair model^[93]

Fig. 5. Crystal growth process of HEM

Fig. 6. Ti∶sapphire HEM crystal growth equipment

Fig. 7. Ti∶sapphire (Ф157 mm) single crystal grown by HEM^[105]

Fig. 8. Ti∶sapphire single crystals grown by HEM. (a) Ф235 mm×72 mm; (b) Ф242 mm×76 mm

Fig. 9. X-ray rocking curve of Ti∶sapphire crystal^[105]

Fig. 10. Reference laser beam shape and transmittance laser beam shapes passing through different test regions of Ti∶sapphire crystal^[105]

Fig. 11. Absorption spectrum of Ti∶sapphire crystal^[105]

Fig. 12. Study on doping of LaAlO₃ crystal. (a) Rhombic domain in pure LaAlO₃; (b) domain-free structure in Nd,Th∶LaAlO₃ crystal along [100]^[131]

Fig. 13. Output power as function of absorbed power for Nd,Th∶LaAlO₃ crystal^[131]

Fig. 14. Yb∶GdScO₃ crystal^[162]

Fig. 15. Mid-infrared fluoride laser crystals. (a) Ho∶LaF₃; (b) Tm∶LaF₃; (c) Tm∶LiYF₄; (d) Ho∶BaY₂F₈; (e) Ho∶CeF₃; (f) Ho∶PbF₂; (g) Ho∶LiLuF₄; (h) Ho, Pr∶LiLuF₄; (i) Tm∶LiLuF₄

Fig. 16. Tm∶LiYF₄ crystal with 3-inch diameter

Fig. 17. Tm∶GdScO₃ crystal, fluorescence spectrum, and continuous wave laser performance^[213-214]

Fig. 18. Comparison of absorption and emission bandwidth of Tm³⁺-doped crystals^[213]

Fig. 19. Diamond grown on surface of YAG crystal. (a) YAG crystals with diamond films; (b) scanning electron microscope (SEM) image of diamond; (c) comparison of YAG thermal conductivity with diamond/YAG thermal conductivity; (d) YAG transmittance curves before and after diamond growth^[262]

Fig. 20. Growth of diamond on Ti∶sapphire surface using chromium transition layer. (a) XRD patterns of Ti∶sapphire samples with chromium transition layer deposited and Ti∶sapphire samples with diamond grown on transition layer; (b) cross section SEM image of diamond/chromium/Ti∶sapphire; (c) top view of differential charge density of carbon atoms on Cr (110) surface obtained based on VASP software, where yellow represents electron aggregation region and blue represents electron disappearance region^[263]