CN101319386A

CN101319386A - Preparation method of KTP crystal with anti-soil performance

Info

Publication number: CN101319386A
Application number: CNA2008101057158A
Authority: CN
Inventors: 师瑞泽; 肖亚波; 葛世艳; 王国影; 高山虎; 尹利君; 王�忠; 何庭秋
Original assignee: BRIGHT CRYSTALS Tech Inc
Current assignee: BRIGHT CRYSTALS Tech Inc
Priority date: 2008-04-30
Filing date: 2008-04-30
Publication date: 2008-12-10
Anticipated expiration: 2028-04-30
Also published as: CN101319386B

Abstract

The invention discloses a method for preparing a KTP crystal capable of resisting gray track, comprising the following steps that: 1) KH2PO4 and TiO2 as raw materials used to synthesize a KTiOPO4 crystal, and K2HPO4 as the raw material used to synthesize a K4P2O7(K4) solvent are mixed according to a certain ratio, and the initial growth mol ratio of the KTiOPO4 to the K4P2O7 obtained after the chemical reaction is about 0.8; 2) the mixed raw materials are put in a platinum crucible and the solution filling amount is between 75 and 85 percent; 3) the platinum crucible is put in a furnace body, a temperature gradient of the furnace is set to be between 3 and 8 DEG C per 10 centimeters, and the furnace is heated so that the raw materials are melted and react to form an even and stable high temperature solution; and 4) the seed crystal is put in the high temperature solution, the temperature is reduced at a temperature gradient of between 1 and 8 DEG C per 100 hours, and the KTiOPO4 crystal is grown at a temperature interval of between 850 and 820 DEG C. The method utilizes the K4P2O7 solvent to prepare the KTP crystal, reduces the absorption coefficient of the KTP crystal, and has evident anti-gray track performance; therefore, the frequency multiplication conversion efficiency of the KTP is improved further, the KTP crystal has good voltage withstanding and modulation performances and can be used as an electrooptical crystal.

Description

A kind of preparation method with anti-grey mark performance ktp crystal

Technical field

The present invention relates to the crystalline material field, especially a kind of preparation method with anti-grey mark performance ktp crystal.

Background technology

Potassium titanium oxide phosphate (KTiOPO ₄Abbreviation KTP) crystal is the superior non-linear optic crystal of over-all properties of generally acknowledging in the world.It has that nonlinear factor is big, optical homogeneity good, heat conductance is good, see through advantage such as wide waveband, has good physics, chemistry and mechanical property simultaneously, is one of best materials of present middle low power Nd laser apparatus 1.06 μ m frequencys multiplication.Be used widely in fields such as the processing of laser medicine, large-scale integrated circuit, laser communications, military blinding, light stages.From crystal growth, be worked into opto-electronic device, formed fairly large industrial market in the world.

People often adopt o (claiming flux method again) to prepare ktp crystal at present.This method is that reaction at high temperature generates KTP solute and polyphosphate fusing assistant, forms uniform and stable pyrosol with the chemical feedstocks of heterogeneity proportioning by a certain percentage.By slow cooling, pyrosol produces supersaturation, supersaturation drive that solute KTP slowly separates out and crystallization on the seed crystal that is placed in the pyrosol.Existing fusing assistant commonly used is K ₆P ₄O ₁₃Solvent (being called for short K6), the method for preparing ktp crystal with the K6 fusing assistant, its growth temperature range is wide, require lower to temperature control device, growth technique is controlled easily, advantage such as the big growth easily of the crystal amount of separating out high quality and large size crystal and being used widely, but studies show that: this ktp crystal with the preparation of K6 fusing assistant, in the non-linear frequency transformation of high-peak power infrared laser, because the green glow photon energy that frequency multiplication generates is higher, along with the passing of duration of service often causes that the photic damage of ktp crystal device forms grey mark, the formation of ash mark can make and absorb a large amount of fundamental frequency light and frequency multiplication light wave, cause the local serious heating of crystal, destroy the crystalline phase matching conditions thereby generation thermic crystal refractive index changes and cause the shg efficiency of device seriously to descend, cause the bad stability of laser apparatus.Simultaneously, because the K6 fusing assistant is comparatively obvious to the high temperature abtragung of platinum crucible, the platinum ion that degrades enters crystal and has strengthened the crystalline uptake factor, also can cause device along logical light light path heating, reduce the crystalline threshold for resisting laser damage, and then further reduced the non-linear efficient of crystalline.

Summary of the invention

At the problem that prior art exists, the object of the present invention is to provide a kind of low absorption and preparation method blue, the anti-grey mark performance ktp crystal of green light band that have.

For achieving the above object, a kind of preparation method with anti-grey mark performance ktp crystal of the present invention is specially:

1) will synthesize the raw material KH of KTP solute ₂PO ₄And TiO ₂, synthetic K4 fusing assistant raw material K ₂HPO ₄Mix mutually, make the initial soln KTiOPO of gained behind the high-temperature chemical reaction ₄And K ₄P ₂O ₇Mol ratio be 0.7～0.9; The chemical equation of synthetic KTP solute and K4 fusing assistant is:

K4 fusing assistant: 2K ₂HPO ₄---K ₄P ₂O ₇+ H ₂O

Ktp crystal: KH ₂PO ₄+ TiO ₂---KTiOPO ₄+ H ₂O

2) mixing raw material is packed in the platinum crucible, making the solution amount of being full of is 75%～85%;

3) platinum crucible is put into body of heater, thermograde is set in the stove is 3 ℃/10cm～8 ℃/10cm, be warmed up to 1000 ℃ and make raw material fusing reaction, and constant temperature stirs 24h, form uniform and stable pyrosol;

4) in pyrosol, put into seed crystal,, grow KTiOPO for 850 ℃～820 ℃ in solution saturation ratio temperature range with 1 ℃/100h～8 ℃/100h speed cooling ₄Crystal.

Further, described initial soln KTiOPO ₄And K ₄P ₂O ₇Optimum mole ratio be 0.8.

Further, optimum temperature gradation is 5 ℃/10cm in the described stove.

Further, described KTiOPO ₄Crystal is 30～120 days at 850 ℃～820 ℃ growth times of temperature range.

The present invention adopts K ₄P ₂O ₇Fusing assistant prepares ktp crystal, and (using identical platinum crucible, only is common K with the general 1064nm uptake factor of crystal of purity raw material growth to have reduced the uptake factor of ktp crystal greatly ₆P ₄O ₁₃System about 1/10).Laser Experiments and PCI test shows in addition, the ktp crystal of this method growth has good anti-grey mark ability.Therefore because absorb lessly, make that the frequency-doubling conversion efficiency of ktp crystal of this method growth is higher.Z is to the specific conductivity test shows simultaneously, and under the 1000V DC condition, its specific conductivity can reach 10 ^-10The S/cm magnitude, more common K ₆P ₄O ₁₃Low three to four orders of magnitude of the ktp crystal of system growth have shown good withstand voltage properties, also can be used as electro-optic crystal and use.

Description of drawings

Fig. 1 is the anti-grey mark absorptive character figure of the ktp crystal of K4 fluxing agent growth;

Fig. 2 is the ktp crystal absorption curve figure of K4 fluxing agent growth.

Embodiment

Reaction generates the chemical equation of K4 fusing assistant and KTP:

K4 fusing assistant: 2K ₂HPO _4---K ₄P ₂O ₇+ H ₂O

Ktp crystal: KH ₂PO ₄+ TiO ₂---KTiOPO ₄+ H ₂O

With respect to K ₆P ₄O ₁₃Fluxing agent growth KTP, K ₄P ₂O ₇Fusing assistant can stable growth temperature range want narrow many, the growth difficulty is relatively large, and is also less relatively in the temperature range solute KTP of the stable growth amount of separating out.At diameter is 150mm, in the crucible of high 100mm, by suitable proportioning, with the raw material KH of synthetic KTP solute ₂PO ₄And TiO ₂, synthetic K4 fusing assistant raw material K ₂HPO ₄Mix mutually, make that the degree of filling of liquation is 75%～85%, adjusting and making in the crucible temperature tonsure is 3 ℃/10cm～8 ℃/10cmm, helps this crystal growth when the temperature tonsure is 5 ℃/10cm most; Be warmed up to 1000 ℃ and make raw material fusing reaction, and constant temperature stirring 24h, uniform and stable pyrosol formed;

Select different liquation proportionings to carry out growth experiment and measure saturation point:

KTP/K4=1.5mol/mol=0.898g/g, saturation point is about about 965 ℃;

KTP/K4=1.4182mol/mol=0.849g/g, saturation point is about 940 ℃;

KTP/K4=1.28mol/mol, saturation point is about 920 ℃;

KTP/K4=1.162mol/mol=0.6955g/g, saturation point is about 897 ℃

KTP/K4=0.802mol/mol=0.48g/g, saturation point is about 849 ℃; Separate out the back liquation that finishes and begin about about 800 ℃ of temperature of solidification;

Through the raised growth experiment confirm, liquation KTP/K4 proportioning is during greater than 0.9mol/mol, be that initial saturation point temperature is when being higher than 860 ℃, the 2mm zone might generate transparent ktp crystal near the ktp crystal of being grown had only liquid level, bottom crystal interlayer is very serious, and initial saturation point temperature is high more, and interlayer is serious more, and this proportioning zone can not be used for the ktp crystal growth.High quality K ₄P ₂O ₇The fluxing agent growth ktp crystal can only carry out less than 0.9mol/mol in liquation KTP/K4 proportioning.

Wherein be the liquation proportioning, slowly cool to 820 ℃ of crystal mass the bests that the interval grew from 850 ℃ of saturation points with KTP/K4=0.8mol/mol.Temperature is lower than 810 ℃ because liquation will partial coagulation, and viscosity raises, and causes lattice defect easily, should stop growing, and proposes the liquation cooling.

Adopt this method under above-mentioned crucible and temperature situation through 60 days with 1 ℃/100h～8 ℃/100h speed cooling, success grow 40*30*30 (X*Y*Z) mm ³The high quality ktp crystal, no interlayer parcel and light path, weigh 60 surplus gram, the 10*10*2mm that processes ³And 6*6*8mm ³The frequency-doubling crystal device absorbs, resists grey mark performance test and frequency doubling property test.Test shows, the ktp crystal of ktp crystal phase matched angle, frequency multiplication transformation efficiency, damage threshold and the common K6 fluxing agent growth of K4 fluxing agent growth want better.Its 1064nm absorbs as shown in Figure 2,10*10*2mm ³The absorption of ktp crystal 1064nm reaches 20ppm/cm and only is 1/15 of the ktp crystal of common K6 fluxing agent growth.

As shown in Figure 1, in the 400 second time of test, adopt PCI (Photo-thermalCommon-path interferometer) system, use power density 10KW/cm ²(400mw, diameter 0.07mm), 532nm green glow irradiation ktp crystal, pci system 1064nm absorbs basic held stationary, has shown the anti-grey mark effect that it is good.

In addition, cut the thick Z of 1mm to the KTP thin slice, measuring its specific conductivity is 10 ^-9～10 ^-10The S/cm magnitude, each and every one magnitude of the ktp crystal of more common K6 fluxing agent growth little three to four through electric-optically Q-switched experiment, has shown good proof voltage and modulating performance, also can be used as electro-optic crystal and uses.

Also can use other sylvite or phosphate reaction to reach the KTiOPO of generation among the present invention ₄And K ₄P ₂O ₇Mol ratio is 0.7～0.9.

Claims

1, a kind of preparation method with anti-grey mark performance ktp crystal is specially:

K4 fusing assistant: 2K ₂HPO ₄---K ₄P ₂O ₇+ H ₂O

Ktp crystal: KH ₂PO ₄+ TiO ₂---KTiOPO ₄+ H ₂O

2, the preparation method with anti-grey mark performance ktp crystal as claimed in claim 1 is characterized in that described initial soln KTiOPO ₄And K ₄P ₂O ₇Optimum mole ratio be 0.8.

3, the preparation method with anti-grey mark performance ktp crystal as claimed in claim 1 is characterized in that, optimum temperature gradation is 5 ℃/10cm in the described stove.

4, the preparation method with anti-grey mark performance ktp crystal as claimed in claim 1 is characterized in that described KTiOPO ₄Crystal is 30～120 days at 850 ℃～820 ℃ growth times of temperature range.