CN103484939B - Infrared nonlinear optical crystal Ba3BSbS6And its production and use - Google Patents

Abstract

The present invention relates to infrared nonlinear optical crystal Ba₃BSbS₆And preparation method thereof, belong to Inorganic Nonlinear Optical Materials field.Synthesized using high temperature solid-state method, synthesis infrared nonlinear optical crystal Ba₃BSbS₆, belong to hexagonal crystal system, space group isCompound Ba₃BSbS₆Under 2.05 μm of laser excitation, its powder frequency doubling intensity is AgGaS₂3 times.

Description

Infrared nonlinear optical crystal Ba3BSbS6 and its preparation method and application

technical field

The invention relates to a class of crystallographically non-centrosymmetric thioborate compound materials and a preparation method thereof, belonging to the field of inorganic nonlinear optical materials.

Background technique

Infrared nonlinear optical crystals have played an increasingly important role in laser technology, military and civilian applications. However, existing commercial materials, such as ZnGeP ₂ , AgGaS ₂ , LiGaS ₂ , and LiInS ₂ , have defects such as low laser damage threshold, which cannot meet the growing demand for practical applications. Therefore, it is a difficult point and a hot spot in this field to explore and discover new high-efficiency infrared nonlinear optical crystal materials that can simultaneously have a high laser damage threshold and a large nonlinear optical coefficient. Among the numerous chalcogenides, thioborates due to their abundant anionic groups (such as [BS ₃ ] ^3- trigonal planar, [BS ₄ ] ^5- tetrahedral, [B ₃ S ₆ ] ^3- hexa Ring, [B ₄ S ₁₀ ] ^8- giant tetrahedron, [B ₁₀ S ₁₆ S _4/2 ] ⁶ -hypertetrahedron and other larger anionic groups) have aroused our research interest. If the asymmetric units mentioned above can form a non-central structure, especially if [BS ₃ ] ^3- triangular plane or [BS ₄ ] ^5- tetrahedron can be arranged in the same phase to produce a non-central structure compound, then their strong Dipole and polarization can induce a strong SHG response. In addition, studies have shown that thioborates are a class that can combine the wide transmission range and high nonlinearity of sulfides (such as AgGaS ₂ ) and borates (such as LiB ₃ O ₅ and β-BaB ₂ O ₄ ) with high A class of compounds with a laser damage threshold. At present, most of the limited thioborates are ternary phases containing alkali or alkaline earth metal compounds, and most of them have centrosymmetric structures. There is only one reported case of thioborates with nonlinear optical response, that is, the quaternary compound Zn _x Ba ₂ B ₂ S _5+x (x≈0.2) synthesized by SWMartin et al., and its frequency doubling efficiency is about α -50 times that of _SiO2 . The present invention successfully obtains a new compound Ba ₃ BSbS ₆ with a non-central structure by introducing an appropriate amount of the second asymmetric unit [SbS ₃ ] ^3- into the Ba/B/S system. The measurement of powder nonlinear optical properties shows that Ba ₃ BSbS ₆ compound has excellent nonlinear optical properties, which endows the novel compound with excellent infrared nonlinear optical properties. Related work has not been reported in the literature so far.

Contents of the invention

Purpose of the present invention: (1) provide an example of infrared nonlinear optical crystal, its chemical formula is Ba ₃ BSbS ₆ ; (2) provide the preparation method of nonlinear optical crystal Ba ₃ BSbS ₆ ; (3) provide nonlinear optical crystal Ba ₃ Use of BSbS ₆ .

The invention provides a single crystal of nonlinear optical crystal Ba ₃ BSbS ₆ . The single crystal belongs to the hexagonal crystal system, and the space group is Among them, the unit cell parameters of Ba ₃ BSbS ₆ are α=β=90°, γ=120°, Z=3, the unit cell volume is The crystal structure of this compound is shown in Figure 1. The main features of the structure are isolated asymmetric structural units [BS ₃ ] ^3- triangular plane and [SbS ₃ ] ^3- triangular pyramid, with Ba ²⁺ distributed around.

The invention provides a preparation method of nonlinear optical crystal Ba ₃ BSbS ₆ , comprising the following steps: mixing Ba, B, Sb, and S uniformly in a ratio of 3:1:1:6, adopting a high-temperature solid-phase synthesis method, at 820 ℃ sintering, keep the temperature for 100 hours, cool down to 300℃ at a rate of 5℃ per hour, and turn off the furnace; after the sample is cooled to room temperature, the nonlinear optical crystal Ba ₃ BSbS ₆ can be obtained, and the sample powder is tested by XRD. Figure 2.

The invention provides the application of the nonlinear optical crystal Ba ₃ BSbS ₆ , which is characterized in that the nonlinear optical crystal is used for the frequency conversion of the laser output of a laser. The powder frequency doubling test shows that the compound Ba ₃ BSbS ₆ has excellent nonlinear optical properties, and its powder frequency doubling intensity is three times that of AgGaS ₂ (AGS) under 2.05 μm laser excitation. The relevant data are shown in Figure 3. It is expected to have important application value in high-tech fields such as laser frequency conversion, electro-optical modulation, and photorefractive information processing.

Description of drawings

Figure 1 is a schematic diagram of the crystal structure of Ba ₃ BSbS ₆ .

Fig. 2 is the X-ray diffraction pattern of Ba ₃ BSbS ₆ crystal. Wherein, a and b are the experimental and theoretical X-ray diffraction patterns of Ba ₃ (BS ₃ )(SbS ₃ ) crystal, respectively.

Fig. 3 is the relation diagram of frequency doubling intensity reference of Ba ₃ BSbS ₆ crystal powder and AgGaS ₂ (46-74μm) (incident laser wavelength is 2050nm).

detailed description

In the glove box, Ba, B, Sb, and S were mixed evenly in the ratio of 3:1:1:6, placed in a quartz reaction tube, and flame-sealed under high vacuum. The sealed quartz reaction tube is placed in a program-controlled tube furnace. After 35 hours, the temperature is raised to 820°C, kept for 100 hours, and then after 104 hours, it is lowered to 300°C. After that, the furnace power is cut off, and the target can be obtained after naturally cooling down to room temperature. Crystal (X-ray single crystal test) and powder pure phase.

Claims (3)

1. infrared nonlinear optical crystal Ba₃BSbS₆, it is characterised in that：Its molecular formula is Ba₃BSbS₆, belong to hexagonal crystal system, it is empty Between group beCell parameter isα=β=90 °, γ= 120 °, Z=3, unit cell volume is

2. the preparation method of the infrared nonlinear optical crystal described in claim 1, using one-step synthesis, including following step Suddenly：By Ba, B, Sb, S Ba in proportion:B:Sb:S=3:1:1:After 6 is well mixed, using high temperature solid phase synthesis, in 820 DEG C of burnings Knot, is cooled to room temperature, you can obtains compound Ba₃BSbS₆。

3. the nonlinear optical crystal described in claim 1 is used for the frequency transformation of laser device laser output.