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In this paper, an acousto-optic (AO) Q-switch based on α-BaTeMo2O9 (α-BTM) crystal is designed and further applied to generate a laser pulse at 639 nm for the first time. The α-BTM AO Q-switch demonstrates a large diffraction angle of 0.93° and a high diffraction efficiency of 85% at 639 nm. In the experiment, a maximum AO Q-switched output power of 362 mW is achieved at a repetition rate of 30 kHz, under a maximum absorbed pump power of 3.60 W, corresponding to a slope efficiency of 15.2%. With transmittance of T = 3%, the shortest Q-switching pulse width of 54.7 ns is generated at a repetition rate of 1 kHz. Meanwhile, the beam quality factor M2 of the above laser is measured, presenting the magnitude of 1.14 at both x and y directions. Our findings indicate that α-BTM AO Q-switch could act as an excellent switching device at 639 nm which may help to explore potential applications in the visible field.

A Cr4+-doped TiTe3O8 crystal with dimensions up to 21 mm × 21 mm × 11 mm was grown successfully by the top-seeded solution growth method. A high-resolution X-ray diffraction experiment showed that the full width at half-maximum of the rocking curve was 41.90″. Energy-dispersive spectrometry (EDS) and X-ray fluorescence spectroscopy (XRF) proved that Cr4+ ions have been doped into the TiTe3O8 crystal with molar percentage of 4.9%. The Cr:TiTe3O8 crystal exhibited an absorption range from 995 to 1565 nm, which is suitable for passive Q switch at 1064 nm. Then, a passive Q-switching solid-state laser operating at 1064 nm was realized using a Cr:TiTe3O8 crystal as the saturable absorber. The maximum laser pulse energy is calculated to be 0.7 μJ, and the maximum peak power reaches 0.7 W.

The electro-optic (EO) property of hexagonal Cs2TeMo3O12 (CTM) crystal is studied with interference technique at 632.8 nm. Both the value and sign of the EO coefficients have been obtained and confirmed. The largest EO coefficient is 10.4 pm/V for r33 due to its structure distortion along c-axis. The transverse effective EO effect of r33 and the half-wave voltage are calculated to be 11.08 pm/V and 5200V at 1064 nm, respectively. The experimental results show that CTM can be one of promising candidates for the EO applications, especially in the mid-infrared region. [ABSTRACT FROM AUTHOR]

Singlecrystal LiInS2(LIS) is a promising candidate for mid-infrared(MIR) frequency conversion to obtain MIR laser output. Large-sizedLIS crystals with a diameter of 16 mm and a length of 50 mm were grownby the modified Bridgman method. The as-grown LIS crystals were annealedin different atmospheres, and the effects of annealing on the electricaland optical properties were studied in detail. The visible-near-infraredand MIR transmission spectra of the crystals were studied before andafter annealing in different atmospheres. The experimental resultsindicate that the optimal annealing conditions for a grown crystalare to use an atmosphere of LIS vapor at 700 °C for 160 h. Theelectrical properties were investigated before and after annealingin the LIS vapor atmosphere. After proper postgrowth annealing, thequality of the crystal was significantly improved, which resultedin an increase in the damage threshold from 0.9 to 1.2 J/cm2. [ABSTRACT FROM AUTHOR]

Bulk TbCa4O(BO3)3 single crystals with diameter of 25 mm and length of 70 mm were successfully grown by the Czochralski (Cz) method for the first time to the best of our knowledge. The main problems of crystal growth were discussed and solved resulting in a high quality crystal. The crystalline perfection of the as-grown crystal was evaluated with full-width at half-maximum (FWHM) of the rocking curve being 35.05", and the optical homogeneity being 7.76 x 10-5. TbCa4O(BO3)3 crystallizes in the monoclinic space group Cm with unit cell parameters of a = 8.0715(7) Å, b = 16.0000(15) Å, c = 3.5454(3) Å, and β = 101.2550(10)°. Several interesting phenomena of atom occupancy and structure distortion were observed and analysed. Furthermore, the hardness, density, absorption and transmission spectra were measured. The TbCOB crystal has a Mohs hardness value of 5.58, and it exhibits a high transparency ranging from 490 nm to 1500 nm. [ABSTRACT FROM AUTHOR]

The complete set of second-order nonlinear optical (NLO) coefficients of Cs2TeMo3O12 single crystals were obtained using the Maker Fringe techniques. The NLO coefficients d32 and d33 were measured to be on the order of 6.8 and 6.5 pm/V, respectively. Irradiated by 1064 nm laser, the crystal is phase-matchable, and its effective nonlinear coefficient is 4.6 pm/V for type I phase matching at θ = 42.7º. The relationship between the second-order nonlinear properties and the crystal structure is also discussed. Considering its wide transmission range, phase matching, and large effective NLO coefficient, Cs2TeMo3O12 is a good candidate for IR NLO application. [ABSTRACT FROM AUTHOR]

The electro-optic (EO) properties of monoclinic BaTeMo2O9 (BTM) single crystals are studied using the interference technique by applying the external electric field. The measured room temperature free EO coefficients at 632.8 nm are 10.2 and 9.0 pm/V for γ12 and γ41, respectively. The EO effect (-12ni3γijE) of BTM is about three times as high as that of KH2PO4 (KDP) crystal, which makes it a very promising candidate for the EO applications. [ABSTRACT FROM AUTHOR]

BaTeMo2O9 is a noncentrosymmetric single crystal for nonlinear optical applications. In this letter, we report complete set of elastic, dielectric, and piezoelectric constants of BaTeMo2O9 single crystal determined by resonance technique and impedance analysis, the relative constants have been obtained and discussed. Our results show that BaTeMo2O9 crystal has excellent piezoelectric property (d34=30.25 pC/N, s44=36.46 pm2/N) and could be a promising candidate for piezoelectric applications. [ABSTRACT FROM AUTHOR]

Single crystals of the polar material Cs2TeW3O12 (CTW) with dimensions up to 26 × 18 × 4 mm³ were successfully grown using a top-seeded solution growth method. The morphologies of the as-grown crystals have been described and compared with that obtained from the Bravais-Friedel and Donnay-Harker (BFDH) method. The crystal structure of CTW has been solved for the first time using single-crystal X-ray diffraction: the compound crystallizes in polar hexagonal space group P63 (No. 173) with cell parameters a = b = 7.3279(3) Å, c = 12.4075(5) Å, Z = 2, and V = 577.00(4) ų. Thermal analysis shows that CTW is thermally stable up to 820 °C, at which it melts incongruently. Further high-resolution X-ray diffraction experiments gave a full-width at half-maximum of the rocking curve of 33″, indicating a good crystalline quality for the as-grown crystals. Optical transmittance spectra of CTW show a broad transmission range from 410 to 5310 nm. Powder second-harmonic generation (SHG) measurements with a 1064 nm laser indicates that CTW exhibits a strong SHG efficiency of about 1.5 the one of KTiOPO4. Polarization measurements indicate that CTW is not ferroelectric; i.e., the polarization is not "switchable". In addition, CTW is nonhygroscopic and resistant to diluted HNO3 aqua-solution. [ABSTRACT FROM AUTHOR]

A mid-infrared LiInSe2 (LISe) single crystal was successfully grown by the modified vertical Bridgman technique with dimensions of about Ø12 mmx30 mm. A large amount of high purity polycrystalline LISe used for crystal growth was synthesized in one run by a novel two-step synthesis method. The thermal properties of the crystal were carefully investigated by measuring the melting point, specific heat, and thermal diffusivity, and deriving the thermal conductivity. The transmission spectrum showed that the 50% transmittance level extends from 0.65 to 12.6 µm. The excellent thermal conductivity and optical properties indicate that LISe is one of only a few promising candidates for high average power nanosecond OPOs pumped by ~1 µm lasers. [ABSTRACT FROM AUTHOR]