Room Temperature Tm,Ho:YAG Laser Development: A Historical Review and Performance Analysis

In 1987, Kintz et al. demonstrated the first successful operation of a room temperature Tm,Ho:YAG laser pumped by LDs, achieving an output power greater than 2mW [12]. In 1993, Bowman studied the performance of a side-pumped Tm,Ho:YAG laser with varying dopant concentrations of the crystal, but only achieved an average output power of 7.6W [13]. Recently, in 2014, Zhang Chao et al. utilized two side-pumped laser modules with Tm:YAG and Tm,Ho:YAG in the same cavity, generating a cw output power of 37W at 2.1μm. However, the optical-to-optical efficiency of this system was only 3.1% [14].