Thermal Expansion Coefficient of Garnet and Bixbyite Laser Crystals Evaluated by First Principles Calculation

Due to heavy thermal load, highly intense lasers suffer from the unstablility of laser output and the fracture of laser gain media. These thermal effects were caused by the stress birefringence, the focal length of thermal lens, and the thermal shock which are inversely proportional to the linear thermal expansion coefficient ( α ). Most simply speaking, the power extraction limit of the laser gain medium relates to 1/ α.