Stress-free mounting and protection of liquid-cooled solid-state laser media

摘要

A laser structure that reduces thermally-induced mounting stress on low fracture strength solid-state laser rods (e.g. Nd:YLF). A transparent sleeve (14) of relatively high strength optical material that has relatively high thermal conductivity (e.g. MgF₂ or Al₂O₃) is provided around the laser rod (13), and a thin layer (15) of elastomer (e.g. of a silicon gel) is provided between the laser material and the transparent sleeve. This arrangement of laser material, transparent sleeve, and elastomer allows sealing of a cooling fluid flow channel (20) disposed around the laser/sleeve assembly using conventional means without applying stress directly to the laser rod material. This reduces the risk of fracturing the laser rod material due to thermal expansion near the seal (24) and allows the laser to be operated at higher average power levels. The elastomer layer and high thermal conductivity sleeve efficiently conduct heat from the laser rod to the surrounding cooling liquid. This structure also minimizes damage to the surface of the strengthened laser rods due to handling and coolant erosion thereby preserving the thermal stress fracture resistance properties of the laser rod during transport, manufacturing assembly, operation, and maintenance.