Incongruent Melting La_xY_ySc_4-x-y(BO₃)₄: LYSB Nonlinear Optical Crystal Grown by the Czochralski Method

Abstract

Nonlinear optical (NLO) crystals with incongruent melting of La x Y y Sc z (BO 3 ) 4 (x + y + z = 4) (LYSB)-type were grown for the first time, to the best of our knowledge, by the Czochralski method. A special thermal assembly was used and the melt composition, growth direction, and the pulling and rotation rates have been optimized. Good optical quality LYSB crystal with a diameter of about 13 mm and a length of 25 mm has been grown from the La 0.765 Y 0.485 Sc 2.75 (BO 3 ) 4 starting melt composition, along the c-axis direction, using a slow rotation rate of 8−10 rpm and a high pulling rate of 2 mm/h. The grown crystal has an acentric huntite-type structure (space group R32, Z = 3) with cell dimensions a = 9.8098(4) Å and c = 7.9802(3) Å, and its chemical composition was determined to be La 0.78 Y 0.32 Sc 2.90 (BO 3 ) 4 . The optical transmission and the refractive indices were determined, and the second harmonic generation (SHG) and sum frequency generation (SFG, ω + 2ω) properties were reported. The laser damage threshold was also determined to be ∼2.0 GW/cm 2 at 1064 nm (6 ns pulses). The main nonlinear properties of Czochralski-grown LYSB crystal were found to be similar to those of flux-grown LYSB, and comparable to YAl 3 (BO 3 ) 4 (YAB) nonlinear properties. The big advantage of Czochralski-grown LYSB crystals is that they can be grown with large size and high quality, making them promising candidates for various NLO applications, including frequency conversion of high-average power radiation sources.

Synthesis and crystal structures of novel alkali rare-earth orthoborates K3RE3(BO3)4 (RE = Pr, Nd, Sm–Lu)

“…As a consequence, the R 1 factor converged down to 4.66%. After all atoms were anisotropically refined, the final circle converges with R 1 = 2.69%, wR 2 = 3.03% and BASF value of 0.4963 (5), indicating a nearly ''perfect twin'' of K 3 Pr 3 (BO 3 ) 4 . Meanwhile, neither non-positive definite atoms nor obvious residual electron densities were present in the final refinement, and none of the constraints and restraints were used during the whole refinement process.…”

“…[3,4] is one of the most useful orthoborates as a fast decay scintillator; light yields of the polycrystalline present around three times than that of the commercial Bi 4 Ge 3 O 12 (BGO) scintillators. Some rare-earth borates exhibit promising nonlinear optical (NLO) properties such as La x Y y Sc 4-x-y (BO 3 ) 4 [5], Ca 4 REO(BO 3 ) 3 (RE = La, Gd, Y) [6], Cd 4-REO(BO 3 ) 3 (RE = La, Gd and Y) [7], REAl 3 (BO 3 ) 4 (RE = Y, Gd, Lu) [8][9][10] and K 7 MRE 2 (B 5 O 10 ) 3 (M = Ca, Sr, Ba, Zn, Cd, Pb; RE = Sc, Y, Gd, Lu) [11,12]. Rare-earth borates are also suitable candidates to host optically active Er 3? and Yb 3? cations to serve as laser crystals [13,14] and self-frequency doubling crystals [15,16].…”

LGYSB:Nd─High-Performance Lasing in the Near-Infrared Region

“…The pellets were heated to 1300 °C and held for 24 h to obtain the LGYSB:Nd polycrystalline compounds. The compounds were then loaded in an Ir crucible 30 mm in height and diameter placed in the center of a particular thermal setup, previously developed by us. , The Czochralski crystal growth equipment consisted of a high-temperature induction heating furnace with automatic vertical translation and axial rotation modules (ADL-MP crystal growth unit). The growth atmosphere was N 2 gas (99.999% purity) to avoid oxidation of the Ir crucible.…”

“…LGYSB:Nd-type crystals. 8,15,16 Therefore, the scandium content in the starting compounds was fixed at 2.75 (4−w− x−y−z = 2.75). Considering the growth of LGSB:Nd-type crystals, 23,24 the optimal content of La in the initial melts was also fixed to w = 0.628.…”

New Yb:LYSB bifunctional crystal for efficient near-infrared laser emission and self-frequency doubling conversion

“…In this work, we report on the development of Yb:LYSB as new bifunctional laser and NLO crystal. Based on our experience on growing undoped LaxYySc4-x-y(BO3)4 -LYSB -type crystals [1], a special heating assembly that allows an effective control of both B2O3 evaporation and thermal gradients over the crucible and in the melt, was used for the growth of the incongruent melting Yb:LYSB crystal by the Czochralski method (Fig. 1).…”