The Dynamic Behaviour Analysis of Up－Conversion Luminescence in ErP_5O_（14） Glass

ＴｈｅＤｙｎａｍｉｃＢｅｈａｖｉｏｕｒＡｎａｌｙｓｉｓｏｆＵｐ－ＣｏｎｖｅｒｓｉｏｎＬｕｍｉｎｅｓｃｅｎｃｅｉｎＥｒＰ_５Ｏ_（１４）ＧｌａｓｓＴｈｅＤｙｎａｍｉｃＢｅｈａｖｉｏｕｒＡｎａｌｙｓｉｓｏｆＵｐ－ＣｏｎｖｅｒｓｉｏｎＬｕｍｉｎｅｓｃｅｎｃｅ...     

Bi_（2－x）Fe_xTi_4O_（11）体系的拉曼光谱研究

Ｂｉ＿（２－ｘ）Ｆｅ＿ｘＴｉ＿４Ｏ＿（１１）体系的拉曼光谱研究赵明旭，孟进芳（长春教育学院物理系长春１３００６１）（河南大学物理系开封４７５００１）ＩｎｖｅｓｔｉｇａｔｉｏｎｓｏｆＲａｍａｎＳｐｃｔｒａｉｎＢｉ＿（２－ｘ）Ｆｅ＿ｘＴｉ＿４Ｏ＿（１１）...     

R＿（1－x）Pr＿xBa＿2Cu＿3O＿（7－δ）超导T＿c平台的离子尺寸效应

系统地研究了Ｒ＿（１－ｘ）Ｐｒ＿ｘＢａ＿２Ｃｕ＿３Ｏ＿（７－δ）的超导Ｔ＿ｃ与Ｐｒ替代浓度ｘ的关系。发现在离子半径ｒ＿ｉ≤ｒ＿ｉ（Ｄｙ）时，在低Ｐｒ浓度范围内存在一个超导Ｔ＿ｃ平台，并且平台宽度表明一个Ｒ￣（３＋）离子尺寸效应。我们认为，Ｔ＿ｃ平台宽度的离子尺寸效应可能起源于Ｐｒ４ｆ电子局域态的改变。提出一个临界Ｒ￣（３＋）离子半径ｒ＿（ｉｃ），ｒ＿ｉ＞ｒ＿（ｉｃ）时ＲＢａ＿２Ｃｕ＿３Ｏ＿（７－δ）的超导电性消失     

Design of Metal-clad Ti: LiNbO_3 Polarizer

ＤｅｓｉｇｎｏｆＭｅｔａｌ－ｃｌａｄＴｉ：ＬｉＮｂＯ＿３ＰｏｌａｒｉｚｅｒＨＵＨ．Ｚ．，ＣＨＥＮＧＧ．（ＤｅｐａｒｔｍｅｎｔｏｆａｐｐｌｉｅｄＰｙｓｉｃｓ，ＴｉａｎｊｉｎＵｎｉｖｅｒｓｉｔｙ，Ｔｉａｎｊｉｎ３０００７２，Ｃｈｉｎａ）ＧＥＮＦ；ＳＯＮＧ...     

Self-talk of Reflection Hologram During its construction

Ｓｅｌｆ－ｔａｌｋｏｆＲｅｆｌｅｃｔｉｏｎＨｏｌｏｇｒａｍＤｕｒｉｎｇｉｔｓｃｏｎｓｔｒｕｃｔｉｏｎ￥ＬＩＵＤａｈｅ；ＺＨＯＵＪｉｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＰｈｙｓｉｃｓ，ＢｅｉｊｉｎｇＮｏｒｍａｌＵｎｉｖｅｒｓｉｔｙ，Ｂｅｉｊｉｎｇ１００８７５...     

Bifurcation of Dicke Model Driven by Laser Field and Scaling Theory of Critical Exponents Far from Equilibrium

ＢｉｆｕｒｃａｔｉｏｎｏｆＤｉｃｋｅＭｏｄｅｌＤｒｉｖｅｎｂｙＬａｓｅｒＦｉｅｌｄａｎｄＳｃａｌｉｎｇＴｈｅｏｒｙｏｆＣｒｉｔｉｃａｌＥｘｐｏｎｅｎｔｓＦａｒｆｒｏｍＥｑｕｉｌｉｂｒｉｕｍＯＵＦａ（ＣＣＡＳＴ（ＷｏｒｌｄＬａｂｏｒａｔｏｒｙ）Ｐ．Ｏ．...     

Analysis of Optical Equalization in WDM System

ＡｎａｌｙｓｉｓｏｆＯｐｔｉｃａｌＥｑｕａｌｉｚａｔｉｏｎｉｎＷＤＭＳｙｓｔｅｍＳＵＮＪｉａｎＧＵＷａｎｙｉＬＩＧｕｏｒｕｉＸＵＤａｘｉｏｎｇ（ＢｅｉｊｉｎｇＵｎｉｖ．ｏｆＰｏｓｔｓ＆Ｔｅｌｅｃｏｍ．，ＢｅｉｊｉｎｇＰ．Ｏ．Ｂｏｘ１２８，Ｃｈｉｎａ...     

Synthesis of Binary Computer－Generated Hologram by Optimal Recursive Direct Binary Search Algorithm

ＳｙｎｔｈｅｓｉｓｏｆＢｉｎａｒｙＣｏｍｐｕｔｅｒ－ＧｅｎｅｒａｔｅｄＨｏｌｏｇｒａｍｂｙＯｐｔｉｍａｌＲｅｃｕｒｓｉｖｅＤｉｒｅｃｔＢｉｎａｒｙＳｅａｒｃｈＡｌｇｏｒｉｔｈｍ￥ＺＨＡＩＪｉｎｈｕｉ；ＲＵＡＮＹＵ（Ｄｅｐｔ．ｏｆＯｐｔｏｅｌｅｃｔｒｏ...     

Automatic Analysis of the Phase Object Using Projection Moire Deflectometry

ＡｕｔｏｍａｔｉｃＡｎａｌｙｓｉｓｏｆｔｈｅＰｈａｓｅＯｂｊｅｃｔＵｓｉｎｇＰｒｏｊｅｃｔｉｏｎＭｏｉｒｅＤｅｆｌｅｃｔｏｍｅｔｒｙ￥ＷＡＮＧＭｉｎｇ（ＢａｓｉｃＤｅｐａｒｔｍｅｎｔ，ＮａｎｃｈａｎｇＵｎｉｖｅｒｓｉｔｙ，Ｎａｎｃｈａｎｇ３３００２９...     

Ray Tracing Through Diffractive Optical Elements Based on the Principle of Fermat

ＲａｙＴｒａｃｉｎｇＴｈｒｏｕｇｈＤｉｆｒａｃｔｉｖｅＯｐｔｉｃａｌＥｌｅｍｅｎｔｓＢａｓｅｄｏｎｔｈｅＰｒｉｎｃｉｐｌｅｏｆＦｅｒｍａｔＺＨＡＯＬｉｐｉｎｇＷＵＭｉｎｘｉａｎＪＩＮＧｕｏｆａｎ（ＤｅｐａｒｔｍｅｎｔｏｆＰｒｅｃｉｓｉｏｎＩｎｓｔｒｕ...     

Crystalline morphologies of P(VDF-TrFE) (70/30) copolymer films above melting point

To further understand the crystallization behavior from melts of P(VDF-TrFE) (70/30) copolymer, the morphologies of P(VDF-TrFE) copolymer thin and ultra-thin films are studied by AFM. It is found that P(VDF-TrFE) (70/30) copolymer films exhibit morphologic transition from big grains to fiber-like rods above melting point. And this may be on account of the molecule chains plastic flow and self-organization, corresponding to polymer homoepitaxy.     

Observation of the bright photovoltaic spatial soliton in fiber-like photorefractive crystal

We have observed two-dimensional bright photorefractive spatial soliton for the first time in a Ce:KNSBN fiber-like crystal at wave-length of 514.5 nm with the intensity range between 2.83 × 10³ W/cm² and 4.71 × 10³ W/cm², then compared it with the one formed in a bulk sample. By comparison we have found that the intensity of forming a soliton in a fiber-like crystal is 7 9 times that in a bulk crystal due to stronger scattering light and complicated multi-wave interaction. By comparison we have also found that the transverse dimensions of a soliton formed in a fiber-like crystal are about 4% smaller than the ones in a bulk crystal when the experimental geometry remains the same, then we have exploited the theory including the contribution of scattering field to interpret the experimental phenomenon.     

双KTP晶体倍频过程的实验研究(二)——光学参量振荡腔内串接倍频

按第一部分指出的串接方位,将串接的双KTP晶体置于光学参量振荡腔中,并采用控温方式补偿程差,实现双模共振,使倍频效率较内腔单模起振提高近30倍,理论分析与实验结果基本符合。     

Ce:KNSBN光折变类光纤简并四波混频特性研究

研究了Ce:KNSBN光折变类光纤在泵浦光和信号光夹角分别为小角度和大角度两种情况下简并四波混频的基本特性.当夹角较大时,在光折变类光纤内部形成了两个四波混频作用区域,获得了比小角度情况提高4倍的大相位共轭反射率.给出了Ce:KNSBN光折变类光纤中,在入射夹角分别为小角度和大角度两种情况下,相位共轭光反射率分别随信号光光强、两束泵浦光光强比变化的实验结果,并用理论公式进行了拟合,理论分析和实验结果相符.还研究了Ce:KNSBN光折变类光纤四波混频光栅模式和相位共轭光时间响应特性.光折变类光纤的相位共轭响应时间较快,可为秒量级.     

EPR and Optical Absorption Studies of VO2+-Doped Diammonium Hexaaqua Magnesium(II) Sulfate

Electron paramagnetic resonance (EPR) studies of VO²⁺ impurity ion in single crystals of diammonium hexaaqua magnesium(II) sulfate are carried out at 9.5 GHz (X-band) at room temperature. Different spin-Hamiltonian parameters are determined. VO²⁺ is expected to enter the lattice substitutionally. Superhyperfine splitting is also observed. An EPR study of a powder sample is done that supports the data obtained from single crystal studies. Optical absorption studies are also performed at room temperature. The crystal field parameter (D_q), tetragonal parameters (D_s and D_t), and various bonding parameters are evaluated to estimate the covalency and nature of bonding of VO²⁺ with its different ligands.     

偏振控制的Ce:KNSBN类光纤光折变光开关

在Ce:KNSBN光折变类光纤晶体中,用不同偏振的读出光控制衍射光强的大小从而实现光折变光开关的开－关功能.实验结果表明e光读出时的光栅衍射效率是o光读出的310倍,而且衍射效率比不随写入光光强比的变化而变化.与块状晶体做了比较,并用理论进行了分析,在光折变类光纤中的衍射效率比是块状晶体的10倍,光折变类光纤晶体有着更好的光开关性能.     

硫氰酸镉锌晶体的振动光谱和结构

本文通过对硫氰酸镉锌(ZnCd(SCN)4,简称ZCTC)晶体的群论、拉曼光谱分析和理论计算发现,对于具有I4对称性的ZCTC,在结构中具有ZnN4、CdS4畸变四面体,ZnN4与CdS4由电子桥-N=C=S-联结构成三维骨架的空间无限延伸的结构网络,畸变四面体产生的偶极矩通过电子桥传递,微观偶极矩通过电子桥-N=C=S-相互叠加,且方向一致,从而使宏观晶体材料显示出大的非线性效应。     

Recovery of Laser-Diode Coherence Length by a Photorefractive Double Phase-Conjugate Mirror

We report an experimental study of dynamic coupling of two laser diodes (LD’s) with a double phase-conjugate mirror (DPCM) in a Bi₁₂TiO₂₀ fiber-like crystal. After the DPCM is recorded in the crystal, one of the LD’s is switched to the multimode regime, while the other remains lasing in the single longitudinal mode. Nevertheless, the DPCM produces phase locking of the single-mode laser with one of the longitudinal modes of the multimode laser. Only the longitudinal mode survives after the transmission through the DPCM, demonstrating the coherence length recovery of the multimode laser.     

Structural and photoluminescence studies on europium-doped lithium tetraborate(Eu:Li_2B_4O_7) single crystal grown by microtube Czochralski(μT-Cz) technique

Rare earth europium(Eu(3+))-doped lithium tetraborate(Eu:Li_2B_4O_7) crystal is grown from its stoichiometric melt by microtube Czochralski pulling technique(μT-Cz) for the first time. The grown crystals are subjected to powder x-ray diffraction(PXRD) analysis which reveals the tetragonal crystal structure of the crystals. UV–vis–NIR spectral analysis is carried out to study the optical characteristics of the grown crystals. The crystal is transparent in the entire visible region, and the lower cutoff is observed to be at 304 nm. The existence of BO_3 and BO_4 bonding structure and the molecular associations are analyzed by Fourier transform infrared(FTIR) spectroscopy. The results of excitation and emission-photoluminescence spectra of europium ion incorporated in lithium tetraborate(LTB) single crystal reveal that the observations of peaks at 258,297, and 318 nm in the excitation spectra and peaks at 579, 591, 597, 613, and 651 nm are observed in the emission spectra.The chromaticity coordinates are calculated from the emission spectra, and the emission intensity of the grown crystal is characterized through a CIE 1931(Commission International d'Eclairage) color chromaticity diagram.     

Photonic generation of power-efficient FCC-compliant ultra-wideband waveforms using semiconductor optical amplifier （SOA）： theoretical analysis and experiment verification

We theoretically design a power-efficient ultra-wideband pulse generator by combining three monocycle pulses with different weights. We also experimentally demonstrate a feasible scheme to generate such power-efficient ultra-wideband waveforms using cross-phase modulation in a single semiconductor optical amplifier. The designed ultra-wideband pulse fully satisfies the requirements for the spectral mask specified by the Federal Communications Commission with high power efficiency. In the experiment, a power-efficient ultra-wideband waveform with a pulse duration of 310 ps is achieved, and the power efficiency is greatly improved compared with that of a single monocycle pulse or a mixture of two monocycles.