WO2016086426A1

WO2016086426A1 - Infrared nonlinear optical crystal material, method for preparation thereof, and application thereof

Info

Publication number: WO2016086426A1
Application number: PCT/CN2014/093185
Authority: WO
Inventors: 张明建; 郭国聪; 曾卉一; 范玉航; 李淑芳; 李丙轩
Original assignee: 中国科学院福建物质结构研究所
Priority date: 2014-12-05
Filing date: 2014-12-05
Publication date: 2016-06-09

Abstract

Disclosed are a nonlinear optical crystal material, a method for preparation thereof, and an application thereof. The material has excellent infrared nonlinear optical performance, and its frequency doubling strength (granularity of 50-100 microns) can reach 1-3 times that of AgGaS₂ of the same granularity. The powder laser damage threshold of the material can reach 100-260 times that of AgGaS₂of the same granularity, and 1-3 times that of KTiOPO₄(KTP) of the same granularity.

Description

Infrared nonlinear optical crystal material, preparation method and application thereof

Technical field

The present application relates to an infrared nonlinear optical crystal material, a preparation method and an application thereof, and belongs to the field of nonlinear optical materials.

Background technique

Infrared nonlinear optical materials have broad application prospects in civil, scientific research and military, such as molecular spectroscopy, non-invasive medical detection, environmental monitoring, deep space exploration, space telescope, infrared laser radar, laser communication, and photoelectric countermeasures. At present, the 2-20 micron mid-infrared band laser is mainly based on the principle of nonlinear optics and infrared nonlinear optical frequency conversion technology. Commercial far infrared nonlinear crystal mainly AgGaS _{_{_2,}} AgGaSe _2, ZnGeP ₂ and the like. These crystals have been widely used in production, life, research and military equipment, but these crystals also have their own shortcomings, such as low laser damage threshold, large crystal growth difficulties, etc., the comprehensive performance can not meet the needs of a growing variety of applications.

With the development of technology and the improvement of demand, it is necessary to explore infrared nonlinear crystals with more comprehensive performance. Therefore, the exploration and growth of new medium- and far-infrared nonlinear optical crystals is not only a challenge for the synthesis and growth of crystalline materials, but also of great strategic significance for the development of civilian high-tech industries and the enhancement of national defense forces.

Summary of the invention

According to one aspect of the present application, a nonlinear optical crystal material is provided. The material has excellent infrared nonlinear optical performance, and the frequency doubling intensity can reach 1 to 3 times that of the same particle size AgGaS ₂ (abbreviated as AGS), and the powder laser damage threshold can reach 100 to 260 times and the same grain size of the same particle size AgGaS ₂ . KTiOPO ₄ (abbreviated as KTP) is 1 to 3 times.

The nonlinear optical crystal material is characterized by having the molecular formula shown below:

(Zn _x Ga _y )(S _u Se _v )

Where x>0, y>0, u≥0, v≥0, u+v≠0, 2x+3y=2u+2v;

The crystal structure of the nonlinear crystal material belongs to a trigonal system, the space group R3, and the unit cell parameter is

α=β=90°, γ=120°, Z=1

Preferably, in the unit cell parameter,

In the crystal structure, zinc atoms and gallium atoms occupy the same crystallographic position (the crystallographic position is denoted as M), and the ratio of the probability of occurrence of zinc atoms at the M crystallographic position to the probability of occurrence of gallium atoms is x:y. The sulfur atom and the selenium atom occupy the same crystallographic position (the crystallographic position is denoted as R). When both u and v are not 0, the ratio of the probability of the sulfur atom to the selenium atom at the R crystallographic position is u:v . The zinc atom and/or the gallium atom at the M crystallographic position forms a tetrahedron of MR ₄ with the sulfur atom and/or the selenium atom at the four R crystallographic positions, and the tetrahedron forms a three-dimensional network structure by a common apex connection.

According to still another aspect of the present application, there is provided a method of preparing the nonlinear optical crystal material, characterized in that a raw material containing a zinc element, a gallium element, a sulfur element and/or a selenium element is uniformly mixed with a flux. The nonlinear optical crystal material is prepared by a high temperature solid phase method under vacuum.

The raw material containing zinc element, gallium element, sulfur element and/or selenium element includes three possibilities: (1) the raw material contains zinc element, gallium element and sulfur element; (2) the raw material contains zinc element and gallium element And selenium; (3) the raw material contains zinc, gallium, sulfur and selenium.

Preferably, the molar ratio of zinc element, gallium element, sulfur element and selenium element in the raw material is Zn:Ga:S:Se=x:y:u:v; wherein x>0, y>0, u≥0 , v≥0, u+v≠0, 2x+3y=2u+2v.

Preferably, the zinc element in the feedstock is derived from the compound ZnS and/or ZnSe.

Preferably, the gallium element in the feedstock is derived from the compounds Ga ₂ S ₃ and/or Ga ₂ Se ₃ .

Preferably, the sulfur element in the feedstock is derived from the compound ZnS and/or Ga ₂ S ₃ .

Preferably, the selenium element in the feedstock is derived from the compound ZnSe and/or Ga ₂ Se ₃ .

Preferably, the raw material is composed of a compound containing a zinc element, a compound containing a gallium element, a compound containing a sulfur element, and/or a compound containing a selenium element.

Preferably, the fluxing agent is selected from at least one of an alkali metal halide and an alkaline earth metal halide. Further preferably, the flux is selected from the group consisting of sodium chloride, potassium chloride, barium chloride, barium chloride, sodium bromide, potassium bromide, barium bromide, barium bromide, sodium iodide, potassium iodide, iodide At least one of cerium, cerium iodide, magnesium chloride, cerium chloride, magnesium bromide, cerium bromide, magnesium iodide, and cerium iodide. Still more preferably, the fluxing agent is selected from the group consisting of potassium iodide and/or potassium bromide.

A person skilled in the art can select an appropriate amount of flux according to actual needs. Preferably, the mass ratio of the flux to the raw material is a flux: raw material = 1 to 10:1. Further preferably, the mass ratio of the flux to the raw material is a flux: raw material = 1 to 3:1. Still more preferably, the mass ratio of the flux to the raw material is a flux: raw material = 2 to 3:1.

The high temperature solid phase method is to keep the mixture of the raw material and the flux at 700 to 1000 ° C for not less than 24 hours. Further preferably, the high-temperature solid phase method is to leave the mixture of the raw material and the flux at 800 to 1000 ° C for not less than 24 hours. Still more preferably, the high temperature solid phase The method is to place the mixture of the raw material and the flux at 850 to 950 ° C for 1 to 3 days. Still more preferably, the high temperature solid phase method is to leave the mixture of the raw material and the flux at 850 to 900 ° C for 1 to 3 days.

Preferably, in the high-temperature solid phase method, the mixture of the raw material and the flux is first placed at 500 to 700 ° C for not less than 1 hour, and then heated to 850 to 1000 ° C for not less than 24 hours.

According to still another aspect of the present application, there is provided an infrared detector comprising a nonlinear optical crystal material prepared by any of the above-described nonlinear optical crystal materials and/or any of the above methods.

According to still another aspect of the present application, there is provided an infrared laser characterized by comprising any of the above-described nonlinear optical crystal materials and/or the nonlinear optical crystal material prepared by any of the above methods.

The beneficial effects that can be produced by the present application include but are not limited to:

(1) The present application provides a novel nonlinear optical crystal material. The material has excellent infrared nonlinear optical properties, and the frequency doubling intensity (particle size 50-100 micron) can be 1 to 3 times that of the same particle size AgGaS ₂ . Powder laser damage threshold of the material with particle size up AgGaS 100 ~ 260 times of _2, with a particle size KTiOPO ₄ (KTP) from 1 to 3 times.

(2) The present application provides a method for preparing the above nonlinear optical crystal material, which is prepared by a high temperature solid phase method in the presence of a flux. The method has simple steps, and the obtained crystal material has high purity, good crystallinity and high yield, and is suitable for large-scale industrialization. produce.

(3) The nonlinear optical crystal material provided by the present application is a polar crystal with excellent infrared nonlinear optical effect, and is expected to be in the middle and far infrared band, such as laser frequency doubling, sum frequency, difference frequency, optical parametric oscillation, etc. Has important application value.

DRAWINGS

Fig. 1 is a comparison of X-ray diffraction theoretical spectra obtained by fitting X-ray diffraction patterns of sample 1 ^# to sample 4 ^# with sample 7 ^# single crystal data.

2 is a schematic view showing the crystal structure obtained by analyzing the single crystal in Example 3.

Fig. 3 is a graph showing the variation of the frequency doubled intensity with the particle size of the sample 1 ^# to the sample 4 ^# .

Figure 4 is an ultraviolet-visible-near-infrared diffuse reflectance spectrum of sample 2 ^# .

Figure 5 is the infrared transmission spectrum of sample 2 ^# .

detailed description

The invention is described in detail below by means of examples, but the invention is not limited to the examples.

Example 1 Preparation of Powder Crystal Samples

The raw material is mixed with the flux, ground uniformly, placed in a quartz reaction tube, vacuumed to 10 ^-2 Pa, and sealed with a oxyhydrogen flame to seal the quartz reaction tube. The quartz reaction tube is placed in a high temperature furnace and heated to the solid solution temperature for a period of time. Then, after cooling to 300 ° C at a speed not exceeding 5 ° C / hour, the heating is stopped, and the nonlinear optical crystal material is obtained by naturally cooling to room temperature.

Sample number, material type and ratio, flux type and amount, solid solution temperature and holding time As shown in Table 1. The substances indicated by the element symbols in the table are simple substances.

Table 1

Example 2 Preparation of Single Crystal Samples

Samples in Example 1 and the ratio of the same type of raw embodiment ^# 2, the starting materials and flux polishing uniformity placed in a quartz reaction tube is evacuated to 10 ^-2 Pa vacuum and blow with the oxyhydrogen flame sealed quartz reaction tube. Place the quartz reaction tube in a high-temperature furnace, heat to 650 ° C for 2 hours, then raise the temperature to 950 ° C for 24 hours, then cool down to 300 ° C at a speed not exceeding 5 ° C / hour, stop heating, and cool naturally. A single crystal sample of the nonlinear optical crystal material was obtained at room temperature and recorded as sample 7 ^# .

Structural characterization of the sample of Example 3

X-ray powder diffraction phase analysis (XRD) of sample 1 ^# to 7 ^# was carried out on a Rigaku MiniFlex II X-ray diffractometer, Cu target, Kα radiation source (λ = 0.154184 nm). The results showed that the samples 1 ^# to 7 ^# prepared in Examples 1 and 2 were samples of high purity and high crystallinity, and typically represented XRD patterns of samples 1 ^# to 4 ^# in Fig. 1. The XRD spectrum results of sample 5 ^# to sample 7 ^# are the same as those of Fig. 1, that is, the position and shape of the diffraction peak are substantially the same, and the relative peak intensity fluctuates within ±5%. Note that samples 1 ^# to 7 ^# have the same crystal structure.

X-ray single crystal diffraction of sample 7 ^# was carried out on a Mercury CCD type single crystal diffractometer, a Mo target, a Kα radiation source (λ = 0.071107 nm), and a test temperature of 293 K. The structure is parsed through the Shelxtl97 pair. The theoretical XRD diffraction pattern obtained by fitting the single crystal data is compared with the experimentally measured XRD diffraction pattern. As shown in Fig. 1, it can be seen that the XRD diffraction pattern obtained by fitting the single crystal data and the experimentally measured XRD diffraction pattern. Highly consistent, the resulting samples proved to be samples of high purity and high crystallinity.

The results of the crystallographic data of sample 7 ^# are shown in Table 2, and the crystal structure diagram is shown in Fig. 2. The valences of zinc, gallium and sulfur atoms are +2, +3 and -2, respectively. In the crystal structure, zinc atoms and gallium atoms occupy the same crystallographic position (the crystallographic position is denoted as M), and the ratio of the probability of occurrence of zinc atoms at the M crystallographic position to the probability of occurrence of gallium atoms is 2:3. The zinc atom and/or the gallium atom form a tetrahedron of MS ₄ with four sulfur atoms, and the tetrahedron forms a three-dimensional network structure by a common apex connection.

Table 2 Crystallographic data

^a R1=||F _o |–|F _c ||/|F _o |.

^b wR ² =[w(F _o ² -F _c ² ) ² ]/[w(F _o ² ) ² ] ^1/2 .

Elemental characterization of the sample of Example 4

The elemental composition of sample 1 ^# to 7 ^# was measured by Ultima 2 type inductively coupled plasma optical emission spectroscopy (ICP) of Jobin Yvon, and the results are shown in Table 3.

table 3

样品编号Sample serial number	元素分析结果Elemental analysis result
样品编号Sample serial number	元素分析结果Elemental analysis result	1^# 1 ^#	(Zn_0.19Ga_0.78)S_1.39 (Zn _0.19 Ga _0.78 )S _1.39
2^# 2 ^#	(Zn_0.41Ga_0.61)S_1.31 (Zn _0.41 Ga _0.61 )S _1.31	1^# 1 ^#	(Zn_0.19Ga_0.78)S_1.39 (Zn _0.19 Ga _0.78 )S _1.39
2^# 2 ^#	(Zn_0.41Ga_0.61)S_1.31 (Zn _0.41 Ga _0.61 )S _1.31	3^# 3 ^#	(Zn_0.59Ga_0.41)S_1.21 (Zn _0.59 Ga _0.41 )S _1.21
4^# 4 ^#	(Zn_0.78Ga_0.21)S_1.09 (Zn _0.78 Ga _0.21 )S _1.09	3^# 3 ^#	(Zn_0.59Ga_0.41)S_1.21 (Zn _0.59 Ga _0.41 )S _1.21

5^# 5 ^#	(Zn_0.19Ga_0.78)S_0.21Se_1.21 (Zn _0.19 Ga _0.78 )S _0.21 Se _1.21
5^# 5 ^#		6^# 6 ^#	(Zn_0.49Ga_0.51)Se_1.26 (Zn _0.49 Ga _0.51 ) Se _1.26
7^# 7 ^#	(Zn_0.39Ga_0.61)S_1.29 (Zn _0.39 Ga _0.61 )S _1.29	6^# 6 ^#	(Zn_0.49Ga_0.51)Se_1.26 (Zn _0.49 Ga _0.51 ) Se _1.26

Example 5 Determination of Optical Properties of Sample 1 ^# ～7 ^#

The second-order nonlinear effects of sample 1 ^# to 7 ^# were tested on a Kurtz-Perry system, and the UV-Vis-NIR diffuse reflectance spectra were measured on a Perkin-Elmer Lambda 950 UV-Vis-NIR spectrometer. The spectra were tested on a Bruker 70 Vertex 70 infrared spectrometer. .

The results show that samples 1 ^# to 7 ^# have similar optical properties.

The frequency doubling strength of the samples 1 ^# to 7 ^# having a particle diameter of 50 to 100 μm was 1 to 2 times that of the corresponding particle size AgGaS ₂ . Particle size of 75 to 150 microns Samples ^# 1 - ^# 7 of the laser damage threshold to achieve the appropriate average particle size of commercially available materials AgGaS 100-260 ₂ times, about 1 to 3 times the corresponding size of KTP.

Taking sample 1 ^# ~4 ^# as a typical representative, the laser damage threshold is compared with AgGaS ₂ and KTP as shown in Table 4.

Taking sample 1 ^# as a typical representative, the curve of the frequency doubling intensity as a function of powder particle size is shown in Fig. 3 (incident laser wavelength is 1910 nm). It can be seen that their frequency doubling intensity increases with particle size at 50-100 μm. A maximum occurs and then begins to fall, which is a non-phase matching behavior. This means that quasi-phase matching techniques are required when applying their second-order nonlinear optical properties.

Taking sample 1 ^# as a typical representative, its light transmission performance is shown in Fig. 4 and Fig. 5. It can be seen that its gap is about 3.05 eV. It has good transmission in the 2.5-25 micron range and a wide high transmission window around 22 microns.

Table 4

The above description is only a few examples of the present application, and is not intended to limit the scope of the application. However, the present application is disclosed in the preferred embodiments, but is not intended to limit the application, any person skilled in the art, It is within the scope of the technical solution to make a slight change or modification with the technical content disclosed above, which is equivalent to the equivalent embodiment, without departing from the technical scope of the present application.

Claims

A nonlinear optical crystal material characterized by having the following molecular formula:

(Zn x Ga y )(S u Se v )

Where x>0, y>0, u≥0, v≥0, u+v≠0, 2x+3y=2u+2v;

The crystal structure of the nonlinear crystal material belongs to a trigonal system, the space group R3, and the unit cell parameter is
α = β = 90°, γ = 120°, Z = 1.
The nonlinear optical crystal material according to claim 1, wherein in the unit cell parameter,
A method of preparing a nonlinear optical crystal material according to claim 1, wherein a raw material containing a zinc element, a gallium element, a sulfur element, and/or a selenium element is uniformly mixed with a flux, and then solidified under a vacuum condition. The nonlinear optical crystal material is prepared by a phase method.
The method according to claim 3, wherein the molar ratio of zinc element, gallium element, sulfur element, and selenium element in the raw material is Zn:Ga:S:Se=x:y:u:v;

Where x>0, y>0, u≥0, v≥0, u+v≠0, 2x+3y=2u+2v.
The method according to claim 3, wherein the zinc element in the raw material is derived from the compound ZnS and/or ZnSe; the gallium element is derived from the compound Ga 2 S 3 and/or Ga 2 Se 3 ; the sulfur element is derived from the compound ZnS and/or Or Ga 2 S 3 ; the selenium element is derived from the compound ZnSe and/or Ga 2 Se 3 .
The method of claim 3 wherein said fluxing agent is selected from at least one of an alkali metal halide and an alkaline earth metal halide.
The method according to claim 3, wherein the high-temperature solid phase method is to maintain the mixture of the raw material and the flux at 700 to 1000 ° C for not less than 24 hours.
The method according to claim 3, wherein the high-temperature solid phase method is to firstly mix the raw material and the flux mixture at 500 to 700 ° C for not less than 1 hour, and then raise the temperature to 850 to 1000 ° C. , keep it no less than 24 hours.
An infrared detector characterized by comprising the nonlinear optical crystal material according to any one of claims 1 to 2 and/or the nonlinear optical crystal material prepared by the method according to any one of claims 3 to 8.
An infrared laser characterized by comprising the nonlinear optical crystal material according to any one of claims 1 to 2 and/or the nonlinear optical crystal material prepared by the method according to any one of claims 3 to 8.