Simple and efficient pumping scheme for side-pumped laser rods

Summary form only given. It is difficult to design a pumping chamber with both high coupling efficiency and good pump power deposition, especially for small diameter rods. We circumvent this difficulty by simply putting a reflector directly on the diode bar submount. Namely the copper mount is polished and gold coated in order to reflect the pump light which has not been absorbed by the first path through the rod. By assembling three such diode bars around a 2 mm laser rod calculations show that up to 75% of the pump power is absorbed by a 1.1% doped Nd:YAG rod. It should be pointed out that no guiding or shaping optics is needed and that this simple and robust scheme is insensitive to the alignment of diode bars. The system is scalable by simply adding more diodes around the rod.