Large second-order optical nonlinearities of fresnoite-type crystals in transparent surface-crystallized glasses

Abstract

Second-order optical nonlinearities, d33 values, of fresnoite-type crystals, Ba2TiSi2O8 (BTS), Sr2TiSi2O8 (STS), and Ba2TiGe2O8 (BTG), have been evaluated by measurements on transparent surface-crystallized glasses consisting of fresnoite-type crystals with the Maker fringe technique. It is found that all these crystals show large d33 values, i.e., d33=13±2 pm/V for BTS, d33=7.2±0.4 pm/V for STS, and d33=22±3 pm/V for BTG. In particular, it is emphasized that BTG has an extremely large d33 value, comparable to LiNbO3 single crystal. It is clarified that the d33 value of fresnoite-type crystals increases with increasing c/a ratio in the lattice parameters of their structures. It is suggested that the increase in the c/a ratio results in the elongation of TiO5 pyramidal units along the c axis, consequently enhancing spontaneous polarizations in the fresnoite-type structure. Transparent surface-crystallized glasses consisting of fresnoite-type crystals are candidates for nonlinear optical materials.

Effect of Heat-Treatment Temperature on Optical Properties of Ba2TiSi2O8 Nanocrystallized Glasses

“…17 , 18 On the other hand, according to Cabral et 20 The optical functional nanocrystallized glass based on a silicate system has a significant potential for photonic devices, fiber applications and the formation of the periodic structure of the nanocrystals. Since it is considered that the formation of a crystalline phase in glass, the SHG and PL properties are very sensitive to the heat-treatment conditions, it is of particular interest to examine the crystallization behavior of the 40BaOெ20TiO 2 ெ 40SiO 2 glass and to clarify the correlation between the SHG and PL intensities and the heat-treatment condition.…”

Surface crystallization and second-order optical non-linearity in Gd2O3–Bi2O3–B2O3glasses

“…The glasses with Gd 2 O 3 contents of 8-14 mol% have large densities of over 6 g/cm 3 and large refractive indices of w1.9. Transparent surface crystallized glasses consisting of two kinds of crystalline phases with different morphologies, i.e.…”

“…In particular, it should be pointed out that the optical secondorder non-linearity of d 33 for ferreoelectric Ba 2 TiGe 2 O 8 crystals in transparent crystallized glasses is w10 pm/V, being comparable to d 22 and d 11 of LiNbO 3 single crystal [3]. Very recently, Honma et al [4,5] 3 . Furthermore, they found that some glasses such as 12.5Sm 2 O 3 $30Bi 2 O 3 $57.5B 2 O 3 are crystallized by irradiations of a continuous Nd:YAG laser with a wavelength of lZ1064 nm, giving the formation of non-linear optical crystalline dots and lines [4,5].…”

“…Furthermore, they found that some glasses such as 12.5Sm 2 O 3 $30Bi 2 O 3 $57.5B 2 O 3 are crystallized by irradiations of a continuous Nd:YAG laser with a wavelength of lZ1064 nm, giving the formation of non-linear optical crystalline dots and lines [4,5]. It is, therefore, of particular interest to clarify crystallization behaviors in the ternary glasses of Ln 2 O 3 -Bi 2 O 3 -B 2 O 3 .…”

“…For instance, transparent crystallized glasses consisting of LaBGeO 5 , SrBi 2 Ta 2 O 9 and Ba 2 TiGe 2 O 8 which are noble optical non-linear and ferroelectric crystals have been fabricated [1][2][3]. In particular, it should be pointed out that the optical secondorder non-linearity of d 33 for ferreoelectric Ba 2 TiGe 2 O 8 crystals in transparent crystallized glasses is w10 pm/V, being comparable to d 22 and d 11 of LiNbO 3 single crystal [3]. Very recently, Honma et al [4,5] 3 .…”