Improved saturation in side pumped rod amplifiers using core doped Nd:YAG ceramic rods

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. 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 mum sized grains which are joined together by a sintering process. The investigated idea is to enhance the extraction efficiency via wider beam cross sections. With these methods we were able to enhance the brightness by a factor of two using the rod with a 3 mm diameter doped core and 5 mm cladding diameter, as compared to the 5 mm diameter ordinary Nd:YAG crystal.