Tm: YAG operating on the ³H₄ –³H₆ transition in the 0.82 μm wavelength range. It can be pumped with efficient diode lasers in the 0.78 – 0.8 μm wavelength range. The transition has a small quantum defect for low thermal dissipation. The upper state lifetimes can be long, on the order of a millisecond for good energy storage. It also has sufficient gain bandwidth to support sub-ps-long pulses depending on the host material and temperature of operation. Compared with the single crystal material, the transparent ceramic materials combine the advantages of single crystals and glasses. The transparent ceramic materials are fabricated by solid-state reaction and vacuum sintering. So, they not only possess good optical and thermal properties as fine as single crystals, but also can be fabricated with large size, high concentration. Furthermore, they also have other superiorities, such as short fabrication period, less cost, and multifunctional samples.