Comparative performance of ASE suppressed ceramic Yb:YAG thin disks

We report on the results of an experimental and theoretical investigation of the relevant performance attributes of Yb:YAG thin disk gain elements for use in high brightness resonators. We compare the laser operation, under extremely high pump and laser power densities, of crystalline thin disks to ceramic disks with undoped, amplified spontaneous emission (ASE) suppressing caps. The disks were operated with impingement cooling either directly on the back (high reflecting) surface or on heat spreaders. Although high optical efficiency was generally maintained, we found a marked difference in both the strength of ASE and the thermo-optical performance of the disks.