Abstract:
Lasing properties of a-cut Nd : YVO4 — YVO4 composite vanadate crystals are experimentally studied for the p and s polarisations of radiation at the 4F3/2 — 4I11/2 transition. Polarisation dependences of the lasing characteristics of passively Q-switched Nd : YVO4 — YVO4 lasers with Cr4+ : YAG Q-switches are investigated. It is shown that the laser operates with the highest efficiency in the case of the s-polarised radiation (minimum pulse duration shorter than 1.5 ns, maximum peak power up to 25 kW, maximum peak energy about 35 μJ at a slope efficiency up to 32 %). Frequency conversion to the second and fourth harmonics is demonstrated. Based on this study, a multiwavelength laser with bactericidal and therapeutic effects is developed for treatment of a wide spectrum of diseases.