Diode end pumped composite Tm:YAG rod with undoped ends at room temperature

The lasing characteristics of composite Tm:YAG rod with undoped ends at room temperature are reported. The maximum output power at 2.015 \mum is 6.97 W and the slope efficiency is 41.45%. Focusing point and output coupler are changed to find the optimization condition. The relationship between operation temperature and output power is discussed. Comparison between Tm:YAG and composite Tm:YAG testifies the superiority of composite crystal.