Yinchao Yue

Bi2(IO4)(IO3)3: A New Potential Infrared Nonlinear Optical Material Containing [IO4]3– Anion

A new potential infrared (IR) nonlinear optical (NLO) material Bi(2)(IO(4))(IO(3))(3) was synthesized by hydrothermal method. Bi(2)(IO(4))(IO(3))(3) crystallizes in the chiral orthorhombic space group P2(1)2(1)2(1) (No. 19) with a = 5.6831(11) Å, b = 12.394(3) Å, and c = 16.849(3) Å. It exhibits a three-dimensional framework through a combination of the IO(3), IO(4), BiO(8), and BiO(9) polyhedra and is the first noncentrosymmetric (NCS) structure containing [IO4](3-) anion. Bi(2)(IO(4))(IO(3))(3) has an IR cutoff wavelength of 12.3 μm and belongs to the type 1 phase-matchable class with a moderately large SHG response of 5 × KDP, which is in good agreement with the theoretical calculations.

ReBe2B5O11 (Re = Y, Gd): Rare-Earth Beryllium Borates as Deep-Ultraviolet Nonlinear-Optical Materials

Two novel rare-earth beryllium borates ReBe2B5O11 (Re = Y, Gd) have been discovered. These materials possess a unique structural feature with a platelike infinite ∞(2)[Be2B5O11]3– superlayer, which is first found in beryllium borates. The superlayer can be seen as sandwich-shaped with ∞(1)[B4O8]4– chains linking up with a ∞(2)[Be2BO5]3– sublayer above and below via the B–O–Be bond. Each ∞(2)[Be2B5O11]3– layer is further connected to the neighboring layer through Re3+ cations coordinating with O atoms. Both of these two crystals have very short cutoff wavelengths below 200 nm and exhibit relatively large nonlinear-optical (NLO) effects, indicating their promising applications as good deep-UV NLO crystals.

Growth and nonlinear optical properties of BaAlBO 3 F 2 crystal

BaAlBO3F2 (BABF), a newly developed nonlinear optical (NLO) crystal, was fully investigated for high-power harmonic generation of UV light. This was performed after successfully growing high-quality single crystals in the LiF–B2O3–NaF flux system. Thermal expansion, specific heat, transmittance spectrum, nonlinear optical coefficients, and laser damage threshold were measured. High-power NLO experiments were also conducted for what we believe to be the first time for BABF crystals. Because BABF is absolutely not hygroscopic, the appealing physical, chemical, optical, and NLO properties make BABF a promising NLO crystal for practical application in high-power UV light generation.

LaBeB3O7: a new phase-matchable nonlinear optical crystal exclusively containing the tetrahedral XO4 (X = B and Be) anionic groups

A new noncentrosymmetric lanthanum beryllium borate compound, LaBeB3O7, has been designed and synthesized by spontaneous crystallization with molten flux. In its crystal structure, boron and beryllium atoms are mutual disorder occupied and coordinated with four oxygen atoms forming XO4 tetrahedra (X = B, Be). The XO4 tetrahedra pile up with each other in the alignment toward the c-axis and build up BeB5O18 six-membered rings along the ab plane with La cations located inside the ring channels. Its structure is isotypic to the SrB4O7. LaBeB3O7 melts congruently at 1100 °C and exhibits the short wavelength absorption edge at 220 nm. Second harmonic generation (SHG) on polycrystalline samples was measured using the Kurtz and Perry technique, which indicated that this compound is phase-matchable and the measured SHG coefficient was about 1–2 times that of KH2PO4 (KDP). Theoretical calculations were carried out to explain the increasing of birefringence in this crystal structure. Our preliminary results indicate that LaBeB3O7 is a promising NLO crystal.

266 nm ultraviolet light generation in Ga-doped BaAlBO 3 F 2 crystals.

BaAlBO3F2 (BABF) crystals are a recently developed and promising nonlinear optical material, notably for the third harmonic generation of ultraviolet (UV) light at 355 nm. However, the fourth harmonic generation of UV light at 266 nm has never been obtained by using a BABF crystal due to its relatively small birefringence. We demonstrate that the birefringence of BABF can be effectively increased by doping it with Ga3+. The fourth harmonic generation of UV light at 266 nm was achieved for the first time in a Ga-doped BABF crystal.

Flux growth and 266 nm generation of a GdAl3(BO3)4 crystal

The study focused on optimization of the growing conditions of GdAl3(BO3)4 (GAB). Using Al2O3–B2O3–Li2O–NaF as a flux, inclusion-free GAB crystals with sizes up to 18 × 18 × 35 mm3 were successfully grown using the top-seeded solution growth technique. The preparation of the starting materials, flux selection and optimization of the growing parameters are discussed in the study. Laser radiation at 266 nm was generated for the first time by a type I phase-matching GAB crystal.