Er掺杂和Er/Yb双掺杂光电陶瓷PLZT的上转换发光

研究了Er掺杂和Er/Yb双掺杂的锆钛酸铅(PLZT)光电陶瓷的上转换发光特性,观测到Er掺杂的PLZT样品在540,566nm附近的绿色发光峰,且随着掺杂浓度的增大而增强;Er/Yb双掺杂的PLZT样品除540,566nm附近处的绿色发光峰外,还有一个较弱的668nm的红色发光峰。另外,上转换发光强度与激发强度的对数关系曲线表明样品的绿光发射和红光发射皆为双光子过程,并且利用喇曼光谱进一步分析讨论了其上转换发光的机制。实验和理论分析表明该材料有望制成电光调Q的双功能上转换激光器件。     

掺La锆钛酸铅压电陶瓷(PLZT)在光Kerr效应教学实验中的应用

通过实验表明高掺La的PLZT具有较高的二次电光系数,用PLZT做Kerr效应教学实验具有明显的优势。     

Electro-optic study of PZT ferroelectric ceramics using modulation of reflected light

Electro-optic coefficients of variations in the refractive index of PZT and PLZT ceramic materials induced by ac electric field are estimated using modulation of reflected light. The electro-optic coefficients of PLZT ceramics measured with the aid of conventional birefringence using the phase shift of transmitted radiation and the proposed method of birefringence using the modulation of reflected light are compared.     

Beam steering of external cavity diode laser by an intracavity electro-optic ceramic deflector

A novel beam-steering external cavity diode laser using an intracavity lead lanthanum zirconate titanate(PLZT) electro-optic ceramic deflector is proposed and demonstrated experimentally.The laser consists of a semiconductor laser with single mode fiber coupled output,polarization controller,PLZT electro-optic ceramic deflector,and output concave mirror.By applying proper driven electrical signals on the PLZT electro-optic deflector,the beam deflection angle achieves 5.8 mrad at 1 000 V.A high-speed beam-steering property with less than 120-ns switching time is also observed.Moreover,a good beam quality with Gaussian spatial profile and a linear polarization state are obtained.     

Anisotropic polarization response of polar nanostructures in relaxor-type lead lanthanum zirconate titanate ferroelectric ceramics

Polar nanoregions (PNRs) in relaxor-type PLZT ferroelectric ceramics and their response to the out-of-plane, in-plane electric fields were investigated by the high-resolution piezoresponse force microscopy. Anisotropic polarization switching kinetic behaviors of PNRs were found in relaxor PLZT ceramics. Normal, stable ferroelectric domain states were formed through the coalescence of PNRs in the out-of-plane field, while in the high in-plane electric field, the polarization dynamic behaviors of PNRs show spatial inhomogeneity due to the anisotropy random fields in the ferroelectric PLZT ceramics.     

A PLZT ceramic T.I.R. diffraction modulator

A total internal reflection modulator is described using a prism of PLZT ceramic exhibiting the quadratic electro-optic effect and giving zero-order extinction at around 100 volts (0.67 kV mm^-1).     

可变可转单波片偏振控制器研究

基于PLZT波片的相对相位延迟量可变性和其折射率椭球主光轴的可转性,提出后反馈单个PLZT可变可转波片偏振控制器.采用模拟退火算法进行扰动寻优,仿真结果显示这种控制器是有效的：能将任意输入偏振态转换为稳定的线偏振光而其光强达到总光强的98%以上,在控制过程中相移能在限定范围内变化,避免了由复位重置可能引起的波动.     

Electrooptical properties and photoinduced effects in plzt ceramics applications to optical storage and processing of information

After defining the properties of transparent lead-lanthanum zirconate-titanate ceramics (PLZT) we report the results of holographic and digital recording in quadratic electrooptic ceramics Pb_0.91La_0.09(Zr_0.65Ti_0.35)_0.9775O₃. Photoinduced refractive index changes in these ceramics by deflected and modulated argon laser beams, the behaviour of the diffraction efficiency versus light power density and applied field, the possibility of image selection and optical selective erasure are explained phenomenologically in terms of a photoinduced field model.     

Ferroelectric domain structures in (Pb,La)(Zr,Ti)O<Subscript>3</Subscript> ceramics observed by scanning force microscopy in acoustic mode

Ferroelectric domain structures of transparent (Pb,La)(Zr,Ti)O₃ (PLZT) ceramics were investigated by scanning force microscopy (SFM) in the acoustic mode. The antiparallel domain configuration with a periodic distribution and local inhomogeneity in PLZT ceramics were clearly revealed with this new domain-imaging technique. The imaging mechanism of ferroelectric domains in SFM acoustic mode is discussed in terms of a local piezoelectric vibrator model. PACS 77.84.Dy; 77.80.Dj; 77.65.-j; 77.22.Ej; 07.79.-v     

Exciton effects on nonlinear electro-optic effects in semi-parabolic quantum wires

The nonlinear electro-optic effects in quasi-one-dimensional semi-parabolic quantum wires are studied, in which the exciton effects are taken into account. The analytical expression of the electro-optic co-efficient is derived by compact density-matrix approach. Finally, the numerical results are presented for GaAs/AlGaAs semi-parabolic quantum wires. The results show that the electro-optic coefficient is over two times bigger than that obtained by without considering exciton effects. Furthermore, the electro-optic coefficient is related to the relaxation time.     

Optical and Photoluminescent Properties of Thin-Film ZnO–PLZT Structure in the UV and Visible Spectral Regions

Optics and Spectroscopy - The structural, optical, and photoluminescent properties of the thin-film structure ZnO–PLZT ferroelectric ceramics are studied. The results of X-ray diffraction...     

In-situ Raman spectroscopic study of domain switching of PLZT ceramics

A specially designed apparatus was used to observe in-situ domain switching in lanthanum-doped lead zirconate titanate (PLZT) ceramics by Raman spectroscopy. Using the established technique, the variations in measured Raman spectrum of unpoled and appropriately poled PLZT ceramics under the application of dc voltage and during the process of electric fatigue were examined. It was confirmed that the intensity change in the soft mode of the Raman band is highly dependent on the orientation of the domain switching with respect to the polarization direction of Raman incident light. When the orientation of the specimen with respect to propagation directions (including polarization direction) of incident light and scattered light is appropriate, the Raman spectroscopy can allow a non-destructive and in-situ measurement of the domain switching in a microscopic scale. The relation between the domain switching and the measured Raman spectrum change is discussed for PLZT polycrystalline materials by developing criteria extended from a single-crystal model. PACS 81.70.Fy; 78.30.-j; 62.20.Mk     

Piezoelectric and pyroelectric properties of lead lanthanum zirconate titanate (PLZT) ceramics prepared by sol gel derived nano powders

Lanthanum modified PZT (PLZT) ceramics were prepared with nano powders obtained by the sol gel method and its piezoelectric and pyroelectric behaviour was studied. The piezoelectric properties of the sol gel derived ceramics were compared with the ones prepared by the conventional oxide route. It was found that although the figures of merit of the sol gel derived ones were slightly better (10–15% increase), because of its higher density with respect to conventional ones. The pyroelectric properties of PLZT needs special mention because of its high detectivity and low noise levels. The results are tabulated in the paper and it indicates great figures of merit.     

Experimentally distinguishing electro-optic effects in silicon

Different electro-optic effects, such as Kerr effect, Pockels effect induced by the electric field or strain, and plasma dispersion effect exist in silicon. Experimentally distinguishing these effects is necessary for designing silicon-based electro-optic devices. According to their different polarization dependencies and frequency responses, these effects are measured and distinguished successfully via a transverse electro-optic modulation experiment based on the near-intrinsic silicon sample. The results indicate that Pockels effect induced by the electric field or strain is primary among these effects in the near-intrinsic silicon sample.     

Technology of PLZT ceramics microfibers for multiferroics composites

Compactness and large energy conversion capacity are the main reasons of development of sophisticated ceramics materials in microfibers form, which are prepared for high-speed multiferroic systems and devices. These multifunctional composite applications are owing to coupling of electrical and magnetic properties, as well as additional thermal and mechanical properties. So that, they are suitable for magnetic sensors, electrically tunable non-linear transducers, and non-volatile memories. In our experiment, the thin fibers ceramics have been produced using special environmental chamber where the high temperature sintering can be protected by controlling such parameters as temperature and sintering atmosphere. Consequently, for these purposes structural and physical properties, preparation and thermal synthesis of micrometer sized lead lanthanum zirconate titanate (PLZT) fibers were investigated thoroughly. Since the phase transition properties of PLZT fibers differ much, the production process of fibers suffers from lack of proper high temperature control. Consequently, our experiments should help to eliminate this drawback, so that various technological conditions, parameters, and subsequent sintering atmosphere with different mixtures of PbO and ZrO were experimentally tested. Final conclusions include comparative analysis of obtained PLZT fibers ferroelectric phase transition properties to specific sintering atmosphere.     

Second-harmonic generation in “Cubic” PLZT ceramics

The temperature-dependent optical second-harmonic generation in thermally depoled La-doped lead zirconate titanate (PLZT) ceramics of composition 8/65/35 and 9/65/35 has been studied. A microscopic model for the anomalous phase transition behaviour of these compounds is suggested.     

La掺杂浓度对PLZT薄膜红外光学性质的影响

采用溶胶-凝胶法在Pt/Ti/SiO2/Si衬底上制备了不同La掺杂浓度PLZT(x/40/60)薄膜- x射线衍射分析表明制备的PLZT(x/40/60)薄膜是具有单一钙钛矿结构的多晶薄膜- 通过红外椭圆偏振光谱仪测量了波长为2-5—12-6μm范围内PLZT薄膜的椭偏光谱，采用经典色 散模型拟合获得PLZT薄膜的红外光学常数，同时也拟合获得PLZT薄膜的厚度- 随着La掺杂浓 度的增大，折射率逐渐减小- 而消光系数除PLZT(4/40/60)薄膜外，呈现逐渐增大的趋势- 分析表明这些差异主要与PLZ 关键词： PLZT薄膜 红外光学性质 红外椭圆偏振光谱     

压应力场下PLZT铁电陶瓷的原位Raman观测

铁电陶瓷材料在外场加载下的畴变所引起的材料结构变化,是导致材料性能衰变和破坏的主要原因,Raman光谱技术是一种研究铁电材料畴变和微结构变化的无损伤性及原位微区的观测方法。采用传统固相法合成Zr/Ti原子比为53/478的掺镧锆钛酸铅(PLZT)铁电陶瓷材料 ,采用X射线衍射仪和扫描电子显微镜及Precision_LC铁电测试系统分别对试样进行结构形貌表征和铁电物理性能测试,利用自制的应力加载装置与Raman光谱仪联用,实现不同压应力场作用下试样的原位Raman谱测试,考察和分析Raman谱软模E(2TO)和E(3TO+2LO)+B1的峰强和峰位随散射偏振方向的变化规律。结果表明,不同压应力场下Raman软模E(2TO)和E(3TO+2LO)+B1的峰强均随散射偏振角度呈现正弦式的变化规律,在60°偏振角度上软模峰强最大,在150°偏振角度上软模峰强最小。随着压应力场的增加,在0°和60°偏振角度获得的软模峰强随应力场的增加呈现明显的下降趋势,而在90°和150°偏振角度获得的软模峰强基本不变。压应力场变化对PLZT陶瓷的Raman软模E(2TO)和E(3TO+2LO)+B1的峰位均不产生影响。     

Copper vapor laser with intracavity radiation scanning by a spatial and temporal light modulator based on PLZT ceramics

The results of an experimental study of the output radiation parameters of a copper vapor laser (CVL) with a self-conjugate resonator are presented. TheQ-factor was controlled by diaphragms (slit or circular) and spatial and temporal light modulators (STLM) based on PLZT ceramics.     

Broad-band dielectric spectroscopy of tetragonal PLZT x /40/60

The dielectric behaviour of tetragonal PLZT x/40/60 ceramics doped with lanthanum (x?=?5,?12 and 15%) has been investigated at 100–10¹⁴?Hz. Dielectric, THz and infrared spectra were measured from 500 to 20?K. For x?≥?12 relaxor ferroelectric behaviour was observed. All three samples showed an additional relaxational mode below phonons. Analysis of the phonon modes for ferroelectric PLZT 5/40/60 is presented together with the complete dielectric behaviour.