Abstract

Side pumped laser rods follow a simple and robust pump design. If Gaussian beams are used to extract energy from a side pumped laser material, it is difficult to extract the energy at the boundaries of the rod efficiently [1]. The aim of this investigation is to find out to what end the application of core doped ceramic rods in amplifiers could solve this problem. The core doped ceramic laser rods consist of an undoped YAG cladding around a Nd: YAG core. Both materials are made of 10 μm sized grains which are joined together by a sintering process [2]. The investigated idea is to enhance the extraction efficiency via wider beam cross sections. In contrast to a conventional rod the wings of the beam profile will not be clipped but will be accommodated in the cladding of the core doped rod. Negative impact of diffraction caused by beam clipping can be avoided. Three different rods with an outer diameter of 5 mm are compared with regard to their laser performance. All rods have a doping level of 0.8 at%. Two of them are ceramic rods which have a doped core of 3 mm diameter and 4 mm diameter. The third rod is a 5 mm diameter conventional Nd YAG crystal rod. The rods are characterized with regard to their thermal lens, thermally induced birefringence, their losses and efficiency.

© 2007 IEEE