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紫外激光诱导近化学计量比钽酸锂晶体铁电畴反转 总被引:1,自引:0,他引:1
对紫外激光诱导近化学计量比钽酸锂晶体铁电畴反转进行了实验研究。波长为351 nm的连续紫外激光被聚焦在近化学计量比钽酸锂晶体的-z表面,同时沿与晶体自发极化相反的方向施加均匀外电场。实验证实紫外激光辐照可以有效地降低晶体畴反转所需的矫顽电场,采用数字全息干涉测量技术检测证实在激光辐照区域实现局域畴反转。研究表明采用紫外激光诱导可以实现对近化学计量比钽酸锂晶体铁电畴反转的局域控制。提出了物理机理的理论分析,认为外电场和激光辐照场的共同作用在晶体内部产生高浓度、大尺寸的缺陷结构,缺陷一定程度上降低畴体成核和畴壁运动所需要克服的退极化能和畴壁能,实现激光诱导畴反转。 相似文献
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采用K2O作助熔剂直接拉晶法和气相输运平衡技术制备出了高质量近化学计量比铌酸锂晶体,研究了铌酸锂晶体中的[Li][Nb]比含量对其畴反转结构和极化电场的影响.实验结果表明:随着晶体中[Li][Nb]比的提高,畴极化反转电场呈明显下降趋势,使用近化学计量比铌酸锂晶体,在4.0±0.5kVmm大小极化电场条件下,成功地实现了1.0mm厚度的周期极化畴反转.并用铌酸锂晶体的Li空位缺陷模型对上述实验结果给出了合理的解释.
关键词:
近化学计量比铌酸锂晶体
周期极化
畴反转 相似文献
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钽酸锂(LiTaO3,简称LT)晶体是本世绍60年代人工会成、80年代迅速发展起来的新型功能材料.它具有优良的压电、热电和电光性能,是制作彩电滤波器、热电探测器和电光调制器的较好的材料,在电视工业和激光、红外等科技领域获得了广泛应用.目前,国内外均具备工业生产的规模. 从单晶炉生产出的LT晶体呈多畴结构,使用之前必须对其极化,使之变成单畴结构.不极化或极化不完全的晶体实际上是不能用的涸此极化工序是LT单晶生产中的关键环节之一. 钽酸锂晶体极化方法和装置为有关的生产和科研单位提供了一套省时、省电、省力、省资金的晶体极化先进… 相似文献
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通对周期性极化铌酸锂(periodically poled lithium niobate,PPLN)的微区拉曼和荧光研究,发现小极化子荧光在反转畴与非反转畴呈现不同强度,同时在畴分界壁观察到拉曼禁止谱线.提出一种能够呈现极化光畴图像的非损伤方法,并进一步探讨反向极化过程的机理.
关键词:
周期性极化铌酸锂
微区拉曼
极化子荧光 相似文献
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A high-power 532 nm-pumped multikilohertz nanosecond optical parametric oscillator using a periodically poled 1.0 mol.% MgO-doped stoichiometric lithium tantalate crystal that could be operated from room temperature to 200 degrees C without damage is reported. A broad continuous tuning range from 855 to 1410 nm was achieved within a single domain period. Efficient operation of high peak power and watt level average power with a power conversion of 62.5% was measured. These results show that a high-resolution high average power visible tunable source can be realized. 相似文献
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Illumination of a lithium niobate or lithium tantalate crystal along the crystallographic c axis with coherent light while simultaneously applying an external electrical field through transparent electrodes allows real-time, in situ, nondestructive monitoring of ferroelectric domain patterns. Imaging of the optical near-field through a lens directly visualizes the domain walls, whereas the far-field yields averaged information about the spatial orientation of the domain boundaries. 相似文献
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D. V. Roshchupkin D. V. Irzhak D. V. Punegov 《Bulletin of the Russian Academy of Sciences: Physics》2008,72(2):184-187
The acoustic properties of lanthanum-gallium tantalate crystals and the polar properties of ferroelectric lithium niobate crystals have been investigated by high-resolution X-ray diffraction and topography. It is shown that analysis of the diffraction spectra of acoustically modulated crystals makes it possible to determine the acoustic amplitudes and power flow angles. It was also demonstrated that investigation of the domain structure in ferroelectric crystals under the conditions of the inverse piezoelectric effect allows one to study the domain structure. 相似文献
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Saito N Akagawa K Ito M Takazawa A Hayano Y Saito Y Ito M Takami H Iye M Wada S 《Optics letters》2007,32(14):1965-1967
We report on a sodium D(2) resonance coherent light source achieved in single-pass sum-frequency generation in periodically poled MgO-doped stoichiometric lithium tantalate with actively mode-locked Nd:YAG lasers. Mode-locked pulses at 1064 and 1319 nm are synchronized with a time resolution of 37 ps with the phase adjustment of the radio frequencies fed to acousto-optic mode lockers. An output power of 4.6 W at 589.1586 nm is obtained, and beam quality near the diffraction limit is also achieved in a simple design. 相似文献
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We investigate the influence of visible light on domain inversion in Mg-doped near stoichiometric lithium niobate crystals and find that the switching electric field decreases about 70% above a threshold light intensity. This effect helps us optically control domain switching and produce bulk domain structures on the micrometre scale. Finally, we introduce a model of photo-induced carriers to explain the origin of the reduction of switching electric field. 相似文献
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V. Ya. Shur A. R. Akhmatkhanov I. S. Baturin M. S. Nebogatikov M. A. Dolbilov 《Physics of the Solid State》2010,52(10):2147-2153
Comprehensive study of depolarization field bulk screening was carried out in lithium niobate and lithium tantalate single
crystals with various stoichiometry. Three used complementary methods are based on: 1) dependence of coercive field on delay
time; 2) decrease of optical contrast of domain wall trace; 3) relaxation of light diffraction intensity on domain walls.
The following parameters of bulk screening process were obtained: relaxation time constants, type of relaxation law, maximal
value of bias field and “true” value of coercive field. Advantages and disadvantages of used experimental methods were analyzed. 相似文献
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Continuous-wave oscillation of a singly resonant optical parametric oscillator operating from 619 to 640 nm has been obtained. Parametric gain is created in a MgO-doped periodically poled stoichiometric lithium tantalate crystal pumped at 532 nm. 100 mW of single-frequency red light have been generated. The signal frequency is tunable, and its frequency stabilization on an external reference has been achieved. 相似文献
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Cirmi G Brida D Manzoni C Marangoni M De Silvestri S Cerullo G 《Optics letters》2007,32(16):2396-2398
We extend the concept of broadband phase matching in a noncollinear optical parametric amplifier (NOPA) to the near-IR. In an 800 nm pumped NOPA using periodically poled stoichiometric lithium tantalate, we amplify a spectrum spanning the 1.1-1.7 microm range and corresponding to two optical cycles of the carrier wavelength. A limited portion of the spectrum is compressed by a prism pair down to 16 fs. 相似文献
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Infrared holographic recording in a two-step process is demonstrated in stoichiometric iron-doped lithium tantalate crystals. Through absorption of two intersecting infrared pulses (A = 1064 nm) a temperature grating and thus a modulated pyroelectric field build up. Free electrons, excited by homogeneous light of a shorter wavelength (lambda = 532 nm) drift in this field, and a phase hologram is stored that can be read nondestructively. The change in refractive index depends mainly on the absorption coefficient at the wavelength of the recording light and on the intensity of the infrared light. The proposed method may be extended to telecommunication wavelengths by choice of suitable dopants. 相似文献