Formation of gaseous cavity defect during growth of Nd:YAG single crystals

Chemical bonding theory of single crystal growth and its application to ϕ 3′′ YAG bulk crystal

“…4 Czochralski (Cz) technique is the conventional method for growing YAG single crystals, however, it is still a huge challenge to grow bulk YAG single crystals with low defects. The formation of defects, such as gaseous cavity, 5 has adverse effects on the optical homogeneity of active medium and causes a large area of the grown YAG single crystals to become useless. In general, decreasing the growth rate, increasing the melt mobility, decreasing the gas pressure of the growth atmosphere together with increasing the height of the melt in the crucible are the main practical processing parameters for lowering the concentration of the bubbles.…”

“…In general, decreasing the growth rate, increasing the melt mobility, decreasing the gas pressure of the growth atmosphere together with increasing the height of the melt in the crucible are the main practical processing parameters for lowering the concentration of the bubbles. 5 Therefore, many studies have focused on optimizing the processing parameters to realize the single crystal growth under kinetic control.…”

Study on Growth Interface of Large Nd:YAG Crystals

“…During the late stage of equal-diameter growth, as the liquid level of the melt falls, radiation from the exposed crucible wall decreases the radial temperature difference, ∆T, across the crucible. Equation (3) shows that the critical diameter, d c , decreases as ∆T decreases, and interface inversion occurs when the crystal diameter becomes equal to d c . Similarly, the growth interface can be inverted by increasing the crystal rotation rate.…”

“…Doped yttrium aluminum garnet (YAG) crystals are still the popular material for solid lasers and are the first working material to be used for high-power solids, owing to their good optical uniformity, excellent mechanical and chemical stability, good thermal conductivity, and feasibility for industrial production [1][2][3][4][5]. Currently, a gradual increase in the application of high-power all-solid-state lasers has accelerated the development of solid-state lasers toward high power levels, efficiency, and beam quality.…”

Direct thermal diffusion bonding of Nd:YAG/YAG composite transparent ceramics by vacuum sintering

“…It has been shown experimentally that the primary color centers in transparent vacuum sintered Nd:YAG were F and F + centers as evidenced by optical absorption in the 250-1100 nm wavelength range [30]. Just as most of rare-earth ions doped single crystals [31,32], the bonded ceramics after vacuum sintering are preferred to anneal in air to compensate oxygen vacancies, which caused the in-line transmittance of sample S3 which is higher than that of without annealing sample S2. Meanwhile, the bonding treatment could have effect on sample S2.…”