Optical transmission larger than 1 (T > 1) through ZnS-SiO2/AgOx/ZnS-SiO2 sandwiched thin films

Optical transmission through flat media should be smaller than 1. However, we have observed optical transmission up to T=1.18. The samples were ZnS-SiO2/AgOx/ZnS-SiO2 sandwiched thin films on glass substrate. The supertransmission could only be observed in the near field. We attribute the supertransmission to the lateral propagation relayed by the laser activated and decomposed Ag nanoparticles. (c) 2006 American Institute of Physics.

反式和顺式-1，2-二氰-（4-乙基苯）乙烯结构的谱学分析

合成了2种新型的可溶性四氮杂卟啉中间体：反式-1，2二氰-（4-乙基苯）乙烯和顺式-1，2-二氰（4-乙基苯）乙烯。通过UV-Vis，FFIR，GC／MS，^1H NMR等方法对这2种化合物的结构进行了表征，给出了它们完整的结构信息。分析比较了顺、反异构体结构上的差异，分析两者的紫外-可见光谱（UV-Vis）、红外光谱（FTIR）和核磁共振光谱（^1H NMR）谱图的差异及其产生原因。

Preparation, characterization and gas sensing properties of lead tetra-(tert-butyl)-5,10,1 5,20-tetraazaporphyrin spin-coating films

A spin-coated film of lead tetra-(tert-butyl)-5,10,15,20-tetraazaporphyrin complex (PbTAP(t-Bu)(4)) was obtained and characterized by IR spectra, absorption spectra and atomic force microscopy. The response and recovery characteristics of the film to NH3, NO2 and C2H5OH vapor were investigated at room temperature. In addition, the reversibility and stability of the film to NH3 were also studied. The results indicate that the PbTAP(t-Bu)(4) derivative can be exploited as an NH3 sensor at room temperature. (c) 2007 Elsevier B.V. All rights reserved.

Nickel(II) and copper(II) complexes containing 2-(2-(5-substitued isoxazol-3-yl)hydrazono)-5,5-dimethylcyclohexane-1,3-dione ligands: Synthesis, spectral and thermal characterizations

Two new hydrazone chelating ligands, 2-(2-(5-methylisoxazol-3-yl)hydrazono)-5,5-dimethylcyclohexane-1,3-dione (HL1) and 2-(2-(5-tert-butylisoxazol-3-yl)hydrazono)-5,5-dimethylcyclohexane- 1,3-dione (HL2), and their nickel(II) and copper(II) complexes were synthesized using the procedure of diazotization, coupling and metallization. Their structures were postulated based on elemental analysis, H-1 NMR, ESI-MS, FT-IR spectra and UV-vis electronic absorption spectra. Smooth films of these complexes on K9 glass substrates were prepared using spin-coating and their absorption properties were evaluated. The thermal properties of the metal(II) complexes were investigated by thermogravimetry (TG) and differential thermogravimetry (DTG). Different thermodynamic and kinetic parameters namely activation energy (E

Nd：Y3Sc（1．5）Al（3．5）O（12）透明陶瓷的光谱性能以及激光输出

采用燃烧法制备了Nd：YSAG粉体,经过成型、素烧,最终在氢气气氛中烧结制备了Nd：YSAG透明陶瓷.测试结果表明,Nd：YSAG透明陶瓷具有荧光谱线较宽,荧光寿命较长的特点.激光实验得到的激光输出,斜率效率为23.6%,输出功率为0.36W,输出激光的谱线分布较宽.

Dual-wavelength competitive output in Nd:Y3Sc1.5Al3.5O12 ceramic disk laser

In this paper, we demonstrated a dual-wavelength competitive output in Nd:Y3SC1.5Al3.5O12 ceramic disk laser. Different dual-wavelength output behaviors for Nd:YSAG and Nd:YAG ceramic disk laser were investigated and discussed. By applying the energy transfer model, we suggested the reasonable explanation for this new phenomenon as the disordered replacing of Al3+ ions by Sc3+ ions. The main advantage of the dual-wavelength ceramic laser is the possibility to serve as the seed source to generate Terahertz radiation. (C) 2008 Elsevier B.V. All rights reserved.

Generation of 1.5-12 ns width-tunable 532 nm pulses by adopting laser-induced plasma shutter technique

The pulse-shaping technique has found widespread applications in nonlinear optics and material processing. Experimental research on laser-induced plasma shutter to control the 532 nm pulse width is conducted. The impacts of the total pulse output energy on pulse compression are investigated, and a useful conclusion can be drawn that there exists an optimal value of pulse energy at which the shortest output pulse of 3.23 ns can be obtained without a device for delay-time. Once the device for delay-time is employed to change the optical differences between two laser paths, the pulse width can be further shortened to 1.51 ns. In short, the 1.5-12 ns width-tunable 532 nm laser pulses have been obtained by adopting the laser-induced plasma shutter technique. (C) 2007 Elsevier GmbH. All rights reserved.

铒玻璃在1．54μm实现1 Hz下3 J和5 Hz下0．6 J的激光输出

近年来,随着激光告警、激光指示、风速测量、激光雷达尤其是激光美容等方面的需求逐渐增加,要求掺铒激光玻璃能够实现比以往更高重复频率以及更大能量的激光输出,其中对脉冲能量的要求达1～10 J。

Spectroscopic properties of Er3+-doped tellurite glass for 1.55 mu m optical amplifier

Er3+-doped TeO2-BaO (Li2O, Na2O)-La2O3 tellurite glass system was prepared and their density, characteristic temperatures and optical properties were determined and investigated. For the TeO2-BaO-La2O3-Er2O3 system, composition with 10 mol% BaO presented the highest thermal stability and good infrared transmittance. Intense and broad 1.53 mu m infrared fluorescence were observed under 977 nm diode laser excitation and the most full width at half-maximum (FWHM) is similar to 60nm. According to absorption spectrum, we calculated the optical parameters by means of Judd-Ofelt and McCumber theory such as the fluorescence lifetimes which are about 2.72-3.25 ms and the maximum emission cross-sections which are similar to 1.0pm(2) at 1.531 mu m. The sigma(e) x FWHM value of composition with 10 mol% BaO for gain bandwidth is similar to 600 exceeding those in silicon and phosphate glasses. Our results indicated this kind of tellurite glasses could be used as an ideal host glass for optical amplifier. (c) 2005 Elsevier B.V. All rights reserved.

Spectroscopic properties of Er3+ doped TeO2-BaO (Li2O, Na2O)-La2O3 glasses for 1.5-mu m optical amplifiers

This paper reports on the optical spectroscopic properties and thermal stability of Er3+-doped TeO2-BaO (Li2O,NaO)-La2O3 glasses for developing 1.5-mu m fiber amplifiers. Upon excitation at 977 nm laser diode, an intense 1.53-mu m infrared fluorescence has been observed with a broad full width at half maximum (FWHM) of about 60 nm for the Er3+-doped TeO2-BaO (Li2O, Na2O)-La2O3 glass with 10 mol% of BaO. The calculated fluorescence lifetime and the emission cross-sections of the 1.53-mu m transition are 2.91 ms and similar to 9.97 x 10(-21) cm(2), respectively. It is noted that the gain bandwidth, a, x FWHM, of the TeO2-BaO-La2O3Er2O3 glass is about 600, which is significantly higher than that in silicate and phosphate glasses. Meanwhile, it is interesting to note that the TeO2-BaO-La2O3-Er2O3 glass has shown a high glass thermal stability and good infrared transmittance. As a result, TeO2-BaO (Li2O, Na2O)-La2O3 glass with 10 mol% of BaO has been considered to be more useful as a host for broadband optical fiber amplifier. (c) 2005 Elsevier B.V. All rights reserved.