The investigations of Dy:YAG and Dy,Tb:YAG as potentially efficient GaN blue LD pumped solid state yellow laser crystals

Abstract With the fast development of GaN blue laser diode, Dy3+ doped laser crystals are receiving renewed interests due to their potential yellow laser emission under GaN laser diode pumping. In this study, Dy:YAG and Dy,Tb:YAG with high quality have been grown successfully with Czochralski method. Their spectroscopic properties as well as the energy transfer mechanism between Dy3+ and Tb3+ were discussed in details. The 583 nm emission cross-section of Dy:YAG crystal is improved by co-doping of Tb3+, which indicates the efficient quasi-resonant energy transfer between the Dy3+-6H13/2 state and Tb3+-7F4 state is realized. The thermal properties of Dy:YAG, including specific heat and thermal conductivity, were investigated. The high thermal conductivity suggests the Dy:YAG crystal should be very suitable for high-power laser operation. In addition, considering the high phonon energy of Dy:YAG and Dy,Tb:YAG crystals, the depletion of population on the lower laser level (6H13/2) of Dy3+ could be accelerated. The results suggesting that both Dy:YAG and Dy,Tb:YAG could be highly appraised as excellent competitors for all solid state yellow lasers.