Enhanced beam quality from a laser rod using interstitial dopants

摘要

A laser rod (10) is provided having a tailored gain profile such that the quality of the output beam is enhanced. The laser rod has a concentration of dopant ions having a first valence that is relatively high at the center of the rod and decreases to the surface of the rod. The laser rod further has a concentration of interstitial ions and dopant ions having a second valence that is lower than the first valence, the concentration being relatively high at the surface of the rod and decreasing to the center of the rod. Methods are provided for creating a layer of inactive laser species in the near surface region of a laser rod using interstitial dopant ions and for reducing the near surface absorption of incident photons intended to induce lasing in a laser rod using a layer of inactive laser ions.
This gain guiding is for example achieved by diffusion of Li into Yb:YAG through the cylindrical shell (10a). An increasing concentration of laser active Yb 3+ is thereby created with a maximum in the center of the laser rod (10).