Comparison of Nd:YAG Ceramic Laser Pumped at 885nm and 808nm

Laser performance of 1064 nm domestic Nd：YAG ceramic lasers for 885 nm direct pumping and 808 nm traditional pumping are compared. Higher slope efficiency of 34% and maximum output power of 16.5 W are obtained for the 885nm pump with a 6ram length 1 at.% Nd：YAG ceramic. The advantages for 885nm direct pumping are discussed in detail. This pumping scheme for highly doping a Nd：YAG ceramic laser is considered as an available way to generate high power and good beam quality simultaneously.     

Optical absorption spectra of tourmaline crystals from Altay,China

Tourmaline is an important functional and gem material.The current study examines pink,green,and brownish-green tourmalines from Altay deposit.Based on X-ray fluorescence(XRF) quantitative analyses and ultrariolet-visible-near-infrared(UV-VIS-NIR) spectral analyses in combination with annealing experiments,the color center of tourmaline is found to be related to the d-d transitions of ions or the d-d transitions of exchange coupled ions.Annealing treatment affects the color improvement of tourmaline crystals.