DIFFERENTIAL GEOMETRICAL METHODS IN THE STUDY OF OPTICAL-TRANSMISSION (SCALAR THEORY) .1. STATIC TRANSMISSION CASE

Static optical transmission is restudied by postulation of the optical path as the proper element in a three-dimensional Riemannian manifold (no torsion); this postulation can be applied to describe the light-medium interactive system. On the basis of the postulation, the behaviors of light transmitting through the medium with refractive index n are investigated, the investigation covering the realms of both geometrical optics and wave optics. The wave equation of light in static transmission is studied modally, the postulation being employed to derive the exact form of the optical field equation in a medium (in which the light is viewed as a single-component field). Correspondingly, the relationships concerning the conservation of optical fluid and the dynamic properties are given, and some simple applications of the theories mentioned are presented.

Optical recording properties of metal-azo dye as recording medium with super-resolution near-field structure

A novel metallized azo dye has been synthesized. The absorption spectra of the thin film and thermal characteristic are measured. Static optical recording properties with and without the Bi mask layer super-resolution near-field structure (Super-RENS) of the metal-azo dye are investigated. The results show that the metal-azo dye film has a broad absorbance band in the region of 450-650 nm and the maximum absorbance wavelength is located at 603 nm. It is also found that the new metallized azo dye occupies excellent thermal stability, initiatory decomposition temperature is at 270 degrees C and the mass loss is about 48% in a narrow temperature region (15 degrees C). The complex refractive index N (N = n + ik) is measured. High refractive index (n = 2.45) and low extinction coefficient (k = 0.2) at the recording wavelength 650nm are attained. Static optical recording tests with and without Super-RENS are carried out using a 650nm semiconductor diode laser with recording power of 7mW and laser pulse duration of 200ns. The AFM images show that the diameter of recording mark on the dye film with the Bi mask layer is reduced about 42%, compared to that of recorded mark on the dye film without Super-RENS. It is indicated that Bi can well performed as a mask layer of the dye recording layer and the metallized azo dye can be a promising candidate for recording media with the super-resolution near-field structure.

Synthesis of nickel(II) complexes of alpha-isoxazolylazo-beta-diketones and their absorption of spin-coating films and thermal properties for HD-DVD-R

Three kinds of new nickel(II) complexes of alpha-isoxazolylazo-beta-diketones with blue-violet light absorption were synthesized. Their structures were postulated based on elemental analysis, MS and FT-IR spectra. Smooth films on K9 glass substrates were prepared using the spin-coating method. The absorption properties and thermal stability of these complexes were discussed. The static optical recording test for high density digital versatile disc-recordable (HD-DVD-R) system was also studied. (c) 2005 Elsevier B.V. All rights reserved.

Investigation on the static recording characteristic of super-resolution near-field structure with antimony mask layer

Static recording characteristic of super-resolution near-field structure with antimony (Sb) is investigated in this paper. The recording marks are observed by a scanning electron microscopy (SEM), a high-resolution optical microscopy with a CCD camera and an atomic force microscopy (AFM). The super-resolution mechanism is also analyzed based on these static recording marks. Results show that the light reaching on recording layer is composed of two parts, one is the linear transmissive light (propagating field) and the other is the nonlinear evanescent light in the optical near field. The evanescent light may be greatly enhanced in the center of the spot because Sb will transit from a semiconductor to a metal when it is melted under the high laser power irradiation. This local melted area in the spot center may be like a metal tip in the optical near field that can collect and enhance the information that is far beyond the diffraction limit, which leads to the super-resolution recording and readout. (c) 2005 Elsevier Ltd. All rights reserved.

Design and construction of a static tester for blue ray optical storage

Blue ray optical storage is one of the important trends in the area of information storage, and attracts a number of researchers. Static tester for blue ray optical storage plays an important role in storage media research. We designed and constructed a static tester, in which modularization makes it very convenient to expand function. Employment of modulation/demodulation technique weakens test error so as to increase test precision. Focus move mode and the nano-positioners facilitate the relocation of recording marks. Only one laser with wavelength 406.7 nm is used. In this paper, system design and characteristics are represented in detail, and some experimental results are also given to show that the static tester can perform successfully, acting as research platform for blue ray optical storage. (c) 2005 Elsevier GmbH. All rights reserved.

SbOx thin films used for write-once blue laser recording

SbOx thin films are deposited by reactive dc-magnetron sputtering from all antimony metal target in Ar+O-2 with the relative O-2 content 7%. It is found that the as-deposited films call represent a two-component system comprising amorphous Sb and amorphous Sb2O3. The crystallization of Sb is responsible for the changes of optical properties of the films. The results of the static, test show that the SbOx thin films have good writing sensitivity for blue laser beams and the recording marks are very clear and circular. High reflectivity contrast of about 41% is obtained at a writing power 6 mW and writing pulse width 300 ns. In addition, the films show a good stability after reading 10000 times.

Synthesis, spectroscopic properties and thermal stability of metal(II) tetraazaporphyrin complexes with two strong wavelength absorption

Three kinds of metal(II) tetraazaporphyrin complexes with blue-violet and red light wavelength absorption were synthesized by refluxing tetraazaporphyrin ligand and different metal(II) ions, respectively. Their structures were confirmed by elemental analysis, LDI-TOF-MS, FT-IR and UV-Vis. The solubility of metal(II) tetraazaporphyrin complexes in organic solvents and absorption properties of their chloroform solution and films on K9 glass in the region 250-800 nm were measured. The influence on the difference of absorption maximum from metal(II) tetraazaporphyrin complexes to tetraazaporphyrin ligand by different metal(II) ions was studied. In addition, the thermal stability of the complexes was also evaluated. (c) 2006 Elsevier Ltd. All rights reserved.

氧化铋薄膜用于蓝光可录存储的研究

利用直流磁控溅射法在不同氧氩分压比条件下制备了BiOx薄膜。通过对薄膜在蓝光作用前后的反射率对比度变化的研究发现，氧氩分压比为50％时制备的薄膜具有最佳的光学对比度。利用X射线衍射仪(XRD)、X光电子能谱(XPS)和光谱仪研究了薄膜热处理前后的结构和光谱性质的变化。研究结果表明薄膜光学性质变化主要由薄膜中氧化铋的相变引起。蓝光静态测试结果显示氧氩分压比为50％条件下制备的BiOx薄膜具有很好好的记录敏感度，在11mW的记录功率和800ns的记录脉宽条件下，得到了52％的反射率对比度。此外，BiOx薄膜表现出了非常好的读出稳定性。

The intensity distribution and thermal stability of InnoSlab laser

Partially end-pumped slab laser is an innovative solid state laser, namely InnoSlab. Combining the hybrid resonator with partially end-pumping, the output power can be scaled with high beam quality. In this paper, the output intensity distributions are simulated by coordinate transformation fast Fourier transform (FFT) algorithm, comparing the thermal lens influence. As the simulated curves showed, the output mode is still good when the thermal lens effect is strong, indicating the good thermal stability of InnoSlab laser. Such a new kind of laser can be designed and optimized on the base of this simulation.

Thermal stability and spectroscopic properties of Er3+-doped niobium tellurite glasses for broadband amplifiers

Three Er3+-doped tellurite glasses with compositions of 70TeO(2)-30ZnO, 70TeO(2)-20ZnO-10Nb(2)O(5) and 70TeO(2)-20ZnO-5BaO-5Nb(2)O(5) have been investigated for developing fiber and planar broadband amplifiers and lasers. The optical spectroscopic properties and thermal stability of Er3+-doped tellurite glasses have been discussed. The results show that the incorporation of Nb2O5 increases the thermal stability of Er3+-doped tellurite glasses significantly, Er3+-doped niobium tellurite glasses 70TeO(2)-20ZnO-10Nb(2)O(5) and 70TeO(2)-20ZnO-5BaO-5Nb(2)O(5) exhibit the good thermal stability (DeltaT > 150degreesC), the large emission cross-section (>10 x 10(-21) cm(2)) and broad full width at half maximum (similar to65 nm), will be preferable for broadband Er3+-doped fiber amplifiers. (C) 2004 Elsevier B.V. All rights reserved.

Stability against crystallization and spectroscopic properties of Tm3+ doped fluorophosphate glasses

Fluorophosphate glasses with various content of Al(PO3)(3) were prepared. With the increment of Al(PO3)(3) content, density decreases while refractive index increases, and transition temperature, crystallization peak temperature and melt temperature increase which were suggested by differential scanning calorimetry. These glasses exhibit the best stability against crystallization with 7-9 mol'Yo Al(PO3)(3) content. Normalized Raman spectra were used to analyze structure and phonon state. The increment of Al(PO3)(3) content does not affect phonon energy but results in the augment of phonon density. Absorption spectra were measured. H-3(6) -> F-3(4) transition exhibits absorption at L band of the third communication window. Compared with the energy of Tm3+ excited states in other glass system, F-3(4) energy of Tm3+ in these glasses is considerable higher and H-3(4) energy is considerable lower, and it can be predicted that emission band of H-3(4) -> F-3(4) transition is close to the amplified band of gain-shift Tm3+ doped fiber amplifier. Analyses of Judd-Ofelt theory suggest when Al(PO3)(3) content is no more than 7 mol%, Judd-Ofelt parameters Omega(t) and the lifetime of H-3(4) energy level of TM3+ vary little with the increment of Al(PO3)(3) content, and when Al(PO3)(3) content is more than 7 mol%, Omega(2) and Omega(6) increase and radiative lifetime of H-3(4) energy level of Tm3+ drops sharply with the increment of Al(PO3)(3) content. (c) 2006 Elsevier B.V. All rights reserved.

Effect of bismuth oxide on the thermal stability and Judd-Ofelt parameters of Er 3(+)/Yb3(+) co-doped aluminophosphate glasses

The Er3+/Yb3+ co-doped glasses with compositions of xBi(2)O(3)-(65-x)P2O5-4Yb(2)O(3)-11Al(2)O(3)-5BaO-15Na(2)O (where x = 0, 2.5, 5, 7.5 and 10 mol%) were prepared using the normal melt quench technique. The optical absorption spectra of the glasses were recorded in the wavelength range 300-1700 nm. The effect of Bi2O3 content on the thermal stability and absorption spectra of glasses was investigated. In addition, the Judd-Ofelt parameters and oscillator strengths were calculated by employing Judd-Ofelt theory. It was observed that the positions of the fundamental absorption edge and cut-off wavelength shifted towards red as the content of Bi2O3 increased. However, there were no red shifts found both in the peak wavelength and in the center of mass wavelength of all absorption bands with Bi2O3 content increasing. The results of Judd-Ofelt theory analysis showed that Judd-Ofelt parameters Omega(t), (t = 2, 4, 6) changed sharply when Bi2O3 concentration exceeded 5 mol%. The variation trends of experimental oscillator strength were similar with those of Judd-Ofelt parameters as function of Bi2O3 concentrations. Moreover, differential scanning calorimetry experiments showed that the increases of Bi2O3 content weakened the network structure and then lowered the thermal stability of the glasses. The spontaneous emission probability A(rad), branching ratio beta and the radiative lifetime tau(rad) were also calculated and analyzed. The stimulated emission cross-section of Er3+ was calculated according to the McCumber theory. It was found that the stimulated emission cross-section of Er3+ was monotonically increases with Bi2O3 content increasing. (C) 2006 Elsevier B.V. All rights reserved.

Effect of oxygen substitution by halide ions on structure, thermal stability and upconversion fluorescence in Er3(+)/Yb3(+)-codoped germanium-bismuth glasses

For the first time. effect of halide ions (F-, Cl-, Br-, and I-) introduction on structure, thermal stability, and upconversion fluorescence in Er3+/Yb3+-codoped oxide-halide germanium-bismuth glasses has been systematically investigated. The results show that halide ions modified germanium-bismuth glasses have lower maximum phonon energy and phonon density, worse thermal stability. longer measured lifetimes of I-4(l1/2) level, and stronger upconversion emission than germanium-bismuth glass. All these results indicate that halide ions play an important role in the formation of glass network, and have an important influence on the upconversion luminescence. The possible upconversion mechanisms of Er3+ ion are also evaluated. © 2005 Elsevier Ltd. All rights reserved.

Host dependent thermal stability and frequency upconversion of Er3+-doped heavy metal oxyfluoride germanate glasses

The upconversion properties of Er3+-doped heavy metal oxyfluoride germanate glasses under 975 nm excitation have been investigated. The intense green (551 and 529 nm) and relatively weak red (657 nm) emissions corresponding to the transitions S-4(3/2) -> I-4(15/2), H-2(11/2) -> I-4(15/2) and F-4(9/2) -> I-4(15/2), respectively, were simultaneously observed at room temperature. The content of PbF2 has an important influence on the upconversion luminescence emission. With increasing content of PbF2, the intensities of green (529 nm) and red (657 nm) emissions increase slightly, while the green emission (551 nm) increases markedly. These results suggest that PbF2 has an influence on the green (551 nm) emission more than on the green (529 nm) and red (657 nm) emissions.

Structure and thermal stability of novel fluorophosphate glasses

A systematic investigation on glass formation in the PbF2-InF3-BaHPO4 ternary system has been carried out. These glasses have characterized by IR spectra, Raman spectra and differential thermal analysis. The results show that the structure of these glasses is mainly affected by BaHPO4 and InF3 contents. With decreasing BaHPO4 content, the glass structure gradually transforms from metaphosphate to polyphosphate. When InF3 content is low, it mainly acts as network modifier, when its content is high; it enters glass matrix and forms In(O,F)(6) groups connecting the polymerized phosphorus oxygen species. PbF2 mainly acts as network modifier in this system. Systematic variations of the glass transition temperature and the thermal stability index agree well with these results. The most stable glass with Delta T = 230 degrees C and S = 21.79 K is obtained. (c) 2004 Elsevier B.V. All rights reserved.