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131.
The directions of the phase normals for which extraordinary bright screened solitons can be formed are described analytically.
Formulas are derived for the directions in which extraordinary solitons can exist in lithium niobate for arbitrary orientations
of the external electric field.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 76, No. 3, pp. 403–410, May–June, 2009. 相似文献
132.
133.
宽带准连续光纤激光在周期极化铌酸锂中倍频特性的研究 总被引:3,自引:2,他引:1
双包层光纤激光器和非线性光学材料(如周期性极化的铌酸锂晶体,PPLN)相结合,开辟了实用性非线性光学器件的一个新领域。研究了准相位匹配周期性极化反转铌酸锂晶体对宽带准连续光纤激光倍频的温度特性和频谱特性。在理论上,从准相位匹配相位失配关系出发,推导了晶体温度与抽运源中心波长的关系以及温度响应带宽,并和已报道实验结果进行了比较,二者符合得很好。此外,还推导了倍频周期极化铌酸锂晶体对抽运基频光源的响应谱线带宽。在实验上,采用长度20mm,极化周期6.5μm,厚度0.5mm的周期极化铌酸锂晶体光纤激光器准连续宽带输出进行了倍频,获得了在不同控制温度下的倍频光光谱,并对此进行了详细分析。 相似文献
134.
135.
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
136.
137.
Tunable femtosecond near-infrared source based on a Yb:LYSO-laser-pumped optical parametric oscillator
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We demonstrate a widely tunable near-infrared source from 767 nm to 874 nm generated by the intracavity second harmonic generation(SHG) in an optical parametric oscillator pumped by a Yb:LYSO solid-state laser. The home-made Yb:LYSO oscillator centered at 1035 nm delivers an average power of 2 W and a pulse duration as short as 351 fs. Two Mg O doped periodically poled lithium niobates(Mg O:PPLN) with grating periods of 28.5–31.5 μm in steps of 0.5 μm and19.5–21.3 μm in steps of 0.2 μm are used for the OPO and intracavity SHG, respectively. The maximum average output power of 180 m W at 798 nm was obtained and the output pulses have pulse duration of 313 fs at 792 nm if a sech2-pulse shape was assumed. In addition, tunable signal femtosecond pulses from 1428 nm to 1763 nm are also realized with the maximum average power of 355 m W at 1628 nm. 相似文献
138.
LiNbO3 is a ferroelectric crystal and grows with multi domains. Different domains are separated by boundaries which are known as domain boundaries. Domain walls for congruent and VTE (Vapor Transport Equilibration) treated near stoichiometric lithium niobate samples were visualised in different crystallographic directions using chemical etching technique. The sample is etched in the mixture of HF and HNO3 (in 1:2 volume ratios) for 10 minutes at boiling temperature. Measured domain wall width was found approximately 15‐20 µm for congruent (CLN) and it reduces to 1‐3 µm for VTE treated near stoichiometric (SLN). Activation energies were also measured by two‐probe method and found to be increasing in stoichiometric sample. This activation energy is related to defect density in the crystals. Activation energy is higher for less defective crystals. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
139.
Continuous-wave mid-infrared intracavity singly resonant optical parametric oscillator based on periodically poled lithium niobate
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This paper reports a continuous-wave (CW) mid-infrared intracavity
singly resonant optical parametric oscillator based on periodically
poled lithium niobate (PPLN) pumped by a diode-end-pumped CW
Nd:YVO$_{4}$ laser. Considering the thermal lens effects, it adopted
an optical ballast lens and the near-concentric cavity for better
operation. At the PPLN's grating period of 28.5\,$\mu$m and the
temperature of 140\du, the maximum idler output power of 155\,mW at
3.86\,$\mu$m has been achieved when the 808\,nm pump power is
8.5\,W, leading to an optical-to-optical conversion efficiency of
1.82{\%}. 相似文献
140.
铌酸锂钠钾纳米粉体的溶胶-凝胶法合成及其相转变 总被引:1,自引:0,他引:1
采用化学络合法将Nb2O5转化为可溶性铌盐作为铌源, 用溶胶-凝胶法, 在500~650 ℃成功煅烧合成了平均晶粒尺寸为20~60 nm的纯钙钛矿相铌酸锂钠钾[(Li0.06Na0.47K0.47)NbO3]无铅压电陶瓷粉体. 研究了晶粒尺寸对铌酸锂钠钾纳米粉体相结构的影响. 结果表明, 基于纳米尺寸效应, 随着晶粒尺寸由60减小到20 nm, 铌酸锂钠钾粉体的相结构由正交相逐渐过渡到四方相, 而室温下四方相向立方相的转变将发生在20 nm以下. 相似文献