Optical Properties of the Fresnoite Ba2TiSi2O8 Single Crystal

Abstract

Abstract:In this work, using large-sized single crystals of high optical quality, the optical properties of Ba 2 TiSi 2 O 8 were systematically investigated, including transmission spectra, refractive indices and nonlinear absorption properties. The crystal exhibits a high transmittance (>84%) over a wide wavelength range from 340 to 2500 nm. The refractive indices in the range from 0.31256 to 1.01398 µm were measured, and Sellmeier's equations were fitted by the least squares method. The nonlinear absorption properties were studied by using the open-aperture Z-scan technique, with a nonlinear absorption coefficient measured to be on the order of 0.257 cm/GW at the peak power density of 16.4 GW/cm 2 . Such high transmittance and wide transparency indicate that optical devices using the Ba 2 TiSi 2 O 8 crystal can be applied over a wide wavelength range. Furthermore, the small nonlinear absorption observed in Ba 2 TiSi 2 O 8 will effectively increase the optical conversion efficiency, decreasing the generation of laser damage of the optical device.

Ba2NaClP2O7: Unprecedented Phase Matchability Induced by Symmetry Breaking and Its Unique Fresnoite-Type Structure

“…If the bridging O1 atom takes the high symmetry 2b (2.mm) site as in fresnoite, the Δn is calculated to be 0.003 (Table 1), which is too small to realize a PM behavior, and this is consistent with the NPM behavior observed for Ba 2 TiOSi 2 O 7 . 24 However, in the real crystal, O1 disorders over the four equivalent 4c sites (..m), of which only two will be occupied, owing to the occupancy of 50% (Figure 3a). Since shifting away from the high symmetry (2.mm) site to the low symmetry (..m) site, symmetries of 4-fold axis as well as mirror plane and 2-fold axis are broken.…”

“…Fresnoite, Ba 2 TiOSi 2 O 7 , represents a large family of compounds showing diverse properties of piezoelectric, ferroelectric, electro-optical, pyroelectric, and NLO properties. − Ba 2 TiOSi 2 O 7 has a NCS P 4 bm tetragonal structure in which the orientation of [TiO 6 ] 8– octahedra with alternating long and short Ti–O bond lengths along the polar c axis produces an intense SHG and a {001} cleavage, and the d 0 Ti 4+ confines the absorption edge to about 300 nm . However, Ba 2 TiOSi 2 O 7 is nonphase-matching (NPM), which puts limitations upon its application.…”

Flux Growth and Properties of Volatile Bromine-Containing UV Nonlinear Optical Crystal K3B6O10Br

“…Due to the good monochromaticity, strong directivity, and high brightness, lasers have been used extensively in the fields of industry, communication, and information technology, through applications such as laser welding, laser etching, and free special optical. Benefiting from the frequency conversion by NLO crystals, a UV laser can be expediently and efficiently obtained [1][2][3][4]. Nowadays, some well-known borates, such as β-BaB 2 O 4 (β-BBO) [5], (LiB 3 O 5 ) (LBO) [6], CsLiB 6 O 10 (CLBO) [7] have been commercially applied.…”

A study of the third-order nonlinear susceptibility and nonlinear absorption of inas in the middle infrared region

“…In the work [10], using large-sized single crystals of high optical quality, the optical properties of Ba 2 TiSi 2 O 8 were systematically investigated, including transmission spectra, refractive indices and nonlinear absorption properties over a wide wavelength range from 340 to 2500 nm. In this experiment, the magnitude of χ (3) was about 10 -13 (esu), it is most likely related to electron cloud distortion [13].…”

“…In the mid-infrared (IR) spectrum, where the most powerful and efficient lasers, including the CO 2 molecule, operate, the implementation of phase distortion correction by the wave front reversal method in four-wave mixing (WFR-FWM) with high efficiency is of particular interest. While nonlinear properties of most materials are studied in the visible and near infrared regions of the spectrum [5,[10][11][12].…”