您的当前位置:首页正文

单掺Rb +和Cs +的KTP晶体生长及其电导率

来源:个人技术集锦
维普资讯 http://www.cqvip.com

第36卷第5期 2007年lO月 人 工 晶 体 学 报 JOURNAL OF SYNTHETIC CRYSTALS Vo1.36 No.5 October.2007 Study on the Growth or Conductivities of Rb+or Cs+Doped KTP Crystals CHANG Xin—an,ZANG He-gui,CHEN Xue-all,,XIAO Wei-qiang,ZHANG Shu-feng (College of Material Science and Engineering,Beijing University ofTechnology,Beijing 100022,China) (Received 19 J嘶2007,accepted24 J 2007) Abstract:Rb :KTP and Cs :KTP crystals have been grown respectively by slow cooling method in KTP- K6 high temperature solutions with 5 mo1%Rb or Cs .It is found that the crystl graowth habit has been changed by the doping.The distirbution coefficients of Rb or Cs in corresponding growth system are 0 646 and 0.08 respectively.The lattice parameters a0 and b0 of doped KTP crystal ale slightly longer than those of pure KTP crysta1.By the doping of Rb or Cs .the conductivity along c-direction of KTP crystl decraease obviously,but the transmission properties of KTP crystl ian wave range of 350-1 100nm have not be affected. Key words:doped KTP crystl;garowth habit;distribution coeficient;transmissifon;c-direction conductivity CLC number:078 Document code:A Article ID:1000-985X(2007)05-1052.04 单掺Rb 和Cs 的KTP晶体生长及其电导率 常新安,臧和贵,陈学安,肖卫强,张书峰 (北京工业大学材料科学与工程学院,北京100022) 摘要:采用高温溶液降温法在掺质浓度均为5mo1%的KTP. 溶液中分别生长了单掺Rb 和Cs 的KTP晶体,发现 掺质改变了晶体生长习性,在相应生长体系中掺质Rb 和Cs 的分配系数分别为0.646和0.08,掺质KTP晶体的 晶胞参数00和60比纯KTP晶体者略有增长。通过掺Rb 或Cs ,KTP晶体的c向电导率明显降低,但晶体在350 ~1lOOnm范围内的光透过性质未受影响。 关键词:掺质KTP晶体;生长习性;分配系数;透过;c向电导率 1 Introduction KTP and its family compound crystls have been studiaed and focused on conversion of frequency since they haye been discovered for over thirty years.There are some reports on optic wave guide of KTP crystl and selaf double frequencv effect of doped KTP cryst1.In faact,KTP crystl nota only is a high quality nonlinear optical crvsta1.but also has excellent electro.optical property.Compared with the electo-roptical crystlsa DKDP【K (D H1 )2PO4]and LN(LiNbO3),KTP crystla have been applied universally,which has many advantages such as higher laser threshold.1ower hat wave volftage,smaller dielectirc constant,wider wave length range(0.35-4. Received date:2007-07—19;a咄pted date:2007-07-24 Biography:CHANG Xin.an(1961一),Male,from Hebei province,Associate professor.E-mail:changxinan@bjut・edu・cn 维普资讯 http://www.cqvip.com 第5期 CHANG Xin-an et al:Study on the Growth and Conductivities of Rb or Cs Doped KTP Crystals 1 053 ———————————————————————————————————————————————————————————————————————————————————— ● 4 m)for light transmission,higher heat conductivity,having no moisture absorpti0n and easy t0 pr0cess. Therefore,KTP crystal is also all electro-optical material with very good application prospects. he studies aboutT electro’optical property of KTP crystal have been reported since 1 980. F0r examp1e,the .electro’optical coefficients—y23 and—y33 of KTP crystal have been roughly measured in frequencyd0ubling directi0n e with Massey in 1 980,all the electirc-optical coefficients of KTP crystal have been detennined with inte lerencmethod by Bierlein in 1986 and by Yin Xin in 1988[2,31 respectivelyBut as an electr0.0ptica1 materia1there are .,some special demands in optical quality,crystal sizedielectric characteristics and so onIn additi0n.KTP crysta1 ,.a crystal with two optical axes and complex optical propertiesSo taking KTP as an electro-optica1 crysta1 .develops slowly・ Because of the appearance of high power and long wave laser system in recent years,.such as high average power diode pumping Tm:YAG laser system(A=2.02 m)and Er:YAG laser system(A=290 m),it is obvious that DKDP crystal(transmission wave length range is 0.2-2.0 m)and LN crysta1(has 10wer 1aser threshold)can"t meet the needs of these systems.Therefore,it's very imperative that new electr0—0Dtica1 crysta1 materials are explored,discovered and studied. In this respectKTP crystal becomes the 6rst election because of it ,s, advantages as the above mentioned. So the scientists pay attention increasingly to study on electr0—0Dtica1 application of KTP crysta1.For example,the design experiments of electro.optical Q.switch 0f KTP cI sta1 have .been made by Ti Chuang in 1994 and by Christopher in 1995[ ' ]respectively which pr0duces veIy只00d ef.fectsThe theoretical analysis and the related calculations about KTP crystla applied to Q.switch and frequency.d0ubling simultaneously have been made by J.Q.Yao in 1997 . The conductivity of the KTP crystl grown by oradinary KTP.Khigh temperature soluti0n is very hi只h(ab0ut 6 10 2‘cm)to be as an electro-optical material,and the crystal may become black and 0paque at the acti0n 0f modulation voltage. On the base of analysis to KTP crystal structurewe consider that the one 0f main reas0ns for ,higher conductivities of the crystal is the K passageway along c axis in the crysta1 structure. If K passa只eway is . blocked up by bigger ions,such as Rb or Cs has been made as be10w. ,the conductivity will be decreased obviouslyS0 tt1e experiment ‘ 2 Experimental 2.1 Crystal growth 2.1.1 Reagents KH2PO4(A・R.),K2HPO4‘3H2O(A.R.),TiO2(S.P.),Rb2CO3(C.P.),Cs2CO3(CP.) . 2.1.2 The preparation of the solution for crystal growth he solTution for crystl garowth has been prepared by the reactions as bel0w at the conditi0n 0f heating: 2KH2PO4+2K2HPO4・3H2O:K6P4Ol3+9H2O T KH2PO4+TiO2:KTiOPO4+H2O t he K6P40lT3(K6)is the solvent and KTiOPO4(KTP)is the solute.The doping i0n is 0btained bv the additi0n of Rb2 CO3 or Cs2 CO3 to the solution respectivelyThe concentration of the doping i0n Rb 0r Cs jn the s0luti0n is .5 mo1%according to the concentration of K . At last,the transparent high temperature solution for doped crystal growth has been prepared. 2.1.3 The growth of the doped crystals In corresponding solutions,Rb or Cs doped KTP crystls have been garown respectively by slowco0ling -method,the growth periods are 26 and 24d respectivelythe temperature ranges of growth are 874.854 ̄C and 863. ,8 5 3 c(二.The crystals are colorless,and the crystal sizes are 5 mm×1 4 mm×8 mm and 6 mm×1 5 mm×9 mm 维普资讯 http://www.cqvip.com

1054 人工晶体学报 第36卷 respectively for Rb doped KTP and Cs doped KTP.The experiment shows that the growth habit of doped crystals is different from that of KTP crystal,in the doped growth system,the crystals grow only along b and c directions, the growth rate in a direction is nearly zero;and the solubility of KTP in K6 will increase when the dopant Rb or Cs is added to the growth solution. 2.1.4 Determination of distribution COefficient of doping ions he contents of doping ions in the crTystals have been measured by ICP—AESdoping ions in the growth system are listed in Table 1. Table 1 The distribution coefficients of doping ions in the growth system ,and the distibution coeffricient of It is obvious that doping ions have been added into the crystal successfully.Because the radius of Cs (0.169nm)is bigger than that of Rb (0.148nm),it is more dificult to substitute K (r=0.133nm)by Cs than by Rb in the crystal structure,SO the distribution coeficientf of Rb is biger than that of Cs in crystal rowgth system. 2.2 Measurement of the iattice parameters of the crystals The lattice parameter of Rb doped KTP crystal and Cs doped KTP crystal have been measured exactly by X— ray four—circle difractometer.The result iS listed in Table 2. Table 2 The lattice parameters of doped KTP crystals Table 2 shows that the cells of doped KTP crystals are slightly biger than that of pure KTP crysta1,.Because the radii of doping ions which substitute K in KTP crystl structure aare bigger than K ionbut the concentrations of doping ions are relatively low in the crysta1. 2.3 The tran圊 ion spectra of doped KTP crystals he transmissiTon spectra of Rb:KTP and Cs:KTP crystals have been measured by CARY 2390 Spectrophotometer.The results are shown in Fig.1. Wavelength/n/ll (a) (b) Fig.1 The transmission spectra of the doped KTP crystals 维普资讯 http://www.cqvip.com 第5期 CHANG Xin—an et al:Study。n the Gr。wth and Co—nductivities of Rb ̄or Cs ̄Doped KTP Crystals 1055 —It is can be seen from Fig.1 that the transmission cuI、,es of doPed KTP crystlas are similar to that of pure K I甲, this is due to the falct that the i眦 on Rb and Cs in KTP crystal structure dont absorb the light in wave len ̄h range of 350.1 100nm.That is to say,the opticalm  quality of KTP crystal dont decrease duo to doping・ 2.4 The conductivRies of doped KTP crystals By。rienting,cutting,grinding and polishing and so on,KTP and doped KTP crystlas haVe been pmcessed t。 州_{堇 resistarices of the samples,the result is listed in Table 3 c ∞ l舌_亘 m m -叽 As we expected the result shows that一  the conductivity of KTP crystal decrease obviously because of the doping of Rb+or Cs+.and Cs+doped KTP cryst小 {B al is more effective on decreasing of conductivity than Rb doped KTP cn,stal although the concentration of the former in cr2;_茔 ystal is less than that of the later.This is because Cs。is bigger than Rb+.if it is substituted f∞ or K ,it can block the K passageway along c—direction in KTP crystla structure more e£ ctive1v than the smailer one,Rb .So it cal=删 善w 呻  l be predicted optimistically that if the concentrat on of Cs‘or Rb+in growth solution increase to a certain value,the conductivity in AC field of KTP crystal will decrease to less than 1.00×10加Q~cm一,then i{8 t can satisfy the electro—optical application completely. 3 Conclusions ¨_叫 n 呈∞ i (1)Rb+。r Cs doped KTP cr_{} ystlas have been grown respectirely in c。rresponding s。luti。ns by slow—cooling meth。d.Being dife nt from puro .虽 e KTP crystal,the doped crystlas grow。nly along b and c—directi。ns,the growIh rate in口direction is nearly zero; (2)In the growth systems,the distribution coefficients of Rb or Cs are 0.646 and 0・08・The doping of Rb+and Cs+in KTP crystals lead to slight expanding of the crystla ceU,and dont affect the transmission propetries in wave len ̄h range of 350—1 100nm of KTP crystla; (3)By the d叩ing of山 Rb or Cs唱 m  ,the c。nductiVity along c—directi。n。f KTP crystla decrease。bviously,and Cs doped KTP crystal is more effective in decreasing。f c。nductiVity than Rb doped KTP crystal・ References [1] M删v G A.KoeIlr T M.Willis L J,et a1.Raman and Electro.。ptic Properties of Potassium Titanate Phesphate[J].卸妇d ,l98o,l9 (24):4136. [2] Bierlein J D.Arweiler C B.Elec讷.0ptic and Dielcetric Properties of KTiOPO4[J].App1.Phys.Lett.,1986,49(15):9l7・ [3] Yin Xin,w锄g Jiyang,uu Y舯gang,et a1.Determinati0n。f^Lu Electro-。ptical Coefllcients ofKTiOPO4 Crystal[J]-Act口 口.s ‘,l988, 37(11):l9l1. Ti Chuang,A1an Hays D,Homcio verdun R.Effcet of Dispersi0n on the Operati。n of a KTP Electro-。ptic Q-switch[J]・却 Opt/cs,1994,33 (36):8355. [5] c stolpher Ebbers A,s【ephan velsko P.High Average Power KTiOPO4 Elcetro-optic Q-siwtch[J].App1.Phys・Lett・,1995,67(5):593. [6] Ya0 J Q,sun x w,Kw0k H S.Analysis ofSimuhaneous Q-switching and Frequency Doubli“g in KTP[J].J.胁 t ,l997,44(5):997・ 

因篇幅问题不能全部显示,请点此查看更多更全内容