Study on thermal effect and electro-optically Q-switching of Cr, Tm, Ho: YAG laser

The thermal effect and Q-switching of flashlamp-pumped Cr, Tm, Ho: YAG (CTH: YAG) laser were investigated systematically. The fraction of pump power dissipated as heat in flashlamp-pumped CTH: YAG laser system was evaluated for the first time by measurements and calculations on thermal lens effect. The quasi-steady state and transient temperature distributions of laser rod were numerical simulated. In addition, Electro-optically Q-switching was studied by design of thermal effect compensation resonator. An unusual phenomenon that the optimal delay time of Q-switch in CTH: YAG was shorter than the pump duration was reported for the first time as far as we know. According to the experimental and theoretical calculation results, the main cause of the phenomenon is the long lifetime of lower laser level, followed by up-conversion and fluorescence quenching at high temperature. The mechanism proposed in this paper is of great significance for the design of highly efficient Q-switched CTH: YAG lasers.