共查询到20条相似文献,搜索用时 31 毫秒
1.
Huidan Zeng Guorong Chen Jianrong Qiu Xiongwei Jiang Congshan Zhu Fuxi Gan 《Journal of Non》2008,354(12-13):1155-1158
We report on three-dimensional precipitation of Au nanoparticles in gold ions-doped silicate glasses by a femtosecond laser irradiation and further annealing. Experimental results show that PbO addition plays the double roles of inhibiting hole-trapped centers generation and promoting formation and growth of gold nanoparticles. Additionally, glass containing PbO shows an increased non-linear absorption after femtosecond laser irradiation and annealing. The observed phenomena are significant for applications such as fabrications of three-dimensional multi-colored images inside transparent materials and three-dimensional optical memory, and integrated micro-optical switches. 相似文献
2.
《Journal of Non》2006,352(6-7):646-656
Femtosecond lasers have been applied for materials processing when high accuracy and small structure size are required. Various induced structures have been observed inside glasses after the femtosecond laser irradiation. We report the femtosecond laser induced refractive-index change, space-selective valence state change of active ions, formation of nanograting, and precipitation and distribution of nanoparticles. We systematically studied the morphology of structures that are induced in the bulk of transparent materials by the tightly focused femtosecond laser radiation. Rugby-ball-like asymmetric induced structures were observed inside Ag+-doped silicate glass. These structures are due to the aggregation of Ag nanoparticles at the depth of the focal point. The size of the induced structure depended on the time interval between successive femtosecond laser pulses. In the case of zinc-tellurite glass, TeO2 rich parts were formed in the center of the focal spot, while zinc migrated to the outside. The mechanisms of the observed phenomena are discussed. 相似文献
3.
Yu Teng Jiajia Zhou Geng Lin Jiajie Hua Heping Zeng Shifeng Zhou Jianrong Qiu 《Journal of Non》2012,358(9):1185-1189
The success in construction of three-dimensional micro optical components or devices inside transparent materials is highly dependent on the ability to modify materials’ local structure. Especially, the realization of space-selective manipulation of element distribution is highly desirable since most of optical parameters such as refractive index and luminescence are closely related to element distribution. Up to present, the only way to control selective element distribution is local melting of glass. Here, we reported, for the first time to our knowledge, the success in realization of space-selective manipulation of element distribution in glassy state region (i.e., un-melted region) inside glass with the irradiation of high repetition rate femtosecond laser. Confocal fluorescence spectra and micro-Raman spectra show that the luminescence distribution of Cu+ ions and the glass network structure can be controlled with femtosecond laser irradiation, revealing the potential applications of this technique in the fabrication of functional waveguides and integrated optical devices. 相似文献
4.
Huidan Zeng Yuxia Yang Xiongwei Jiang Guorong Chen Jianrong Qiu Fuxi Gan 《Journal of Crystal Growth》2005,280(3-4):516-520
We report the space selective precipitation of Pd nanoparticles in Pd2+-doped silicate glass by ultrashort laser pulses irradiation and further annealing. Absorption spectra, transmission electron microscopy, refractive index measurement and Z-scan technique demonstrated that metallic Pd nanoparticles were precipitated in the glass sample after irradiation by an 800-nm femtosecond laser and subsequent annealing at 600 °C. We discuss a refractive index change and nonlinear absorption that combines the precipitation of Pd nanoparticles. 相似文献
5.
Guoping Dong Liaolin Zhang Mingying Peng Jianrong Qiu Geng Lin Fangfang Luo Bin Qian Quanzhong Zhao 《Journal of Non》2011,357(11-13):2392-2395
With the irradiation by femtosecond (fs) laser with high repetition rate, GeS2 micro/nano-crystalline formation and microstructural modification occurred in pseudo-binary GeS2–In2S3 glass, while almost no similar change was observed in GeS2 glass. The addition of In2S3 is beneficial for the precipitation of GeS2 micro/nano-crystals. It is expected that functional micro/nano-crystals can be controllably prepared in chalcogenide glasses by fs laser irradiation through glass composition design. 相似文献
6.
O. I. Eroshova P. A. Perminov S. V. Zabotnov M. B. Gongal’skii A. A. Ezhov L. A. Golovan’ P. K. Kashkarov 《Crystallography Reports》2012,57(6):831-835
Silicon nanoparticles have been formed as a result of the irradiation of single-crystal silicon targets in distilled water and liquid nitrogen, by, respectively, picosecond and femtosecond laser pulses. The main structural properties of these nanoparticles have been investigated by atomic force microscopy, transmission electron microscopy, electron diffraction, Raman scattering, and photoluminescence spectroscopy. These particles are found to be mainly spherical. The presence of crystalline and amorphous silicon phases under picosecond ablation in water is established experimentally. Irradiation by femtosecond pulses in liquid nitrogen can yield nanoparticles smaller than 5 nm in size, which are quantum dots with a characteristic photoluminescence peak near 750 nm. 相似文献
7.
Huidan Zeng Chongjun Zhao Jianrong Qiu Yunxia Yang Guorong Chen 《Journal of Crystal Growth》2007,300(2):519-522
Silver nanoparticles were prepared by a focused femtosecond laser irradiation in a 5 mM AgNO3 solution in the presence of TiO2 sol. TEM analysis revealed that the size of silver nanoparticles was less than 20 nm. A mechanism for the precipitation of silver nanoparticles was proposed. Nonlinear absorptions and optical limiting properties of silver nanoparticles contained solution were also measured. It is observed that the composite material showed strong self-focused effect and significant optical limiting property. 相似文献
8.
This paper reports on the formation of nanostructures produced in soda-lime glass by controlling the irradiation conditions of a single-beam femtosecond laser. Periodic nanoholes are fabricated in the sample with the lowest diameter of 200 nm (approximately one fourth of the incident light wavelength). Self-organized nanogratings with a period of 120 nm are fabricated for the first time on soda-lime glass surface by applying many pulses at the same spot. We discover that the nanogratings’ period decreases with the increase of the applied pulses. We investigate that the direction of the nanogratings is perpendicular to the direction of laser polarization. Further, it is discovered that the microholes, due to the illumination by many pulses, are elliptical in shape with the major axis perpendicular to the direction of laser polarization. Finally, long distance horizontal and vertical gratings are fabricated by scanning a femtosecond laser beam only in the horizontal direction. 相似文献
9.
We report on photosensitivities in silver ion doped glasses. We succeeded in precipitation control of silver particles without heat treatment by the irradiation of femtosecond laser pulses. The silver particles can be precipitated in a given location. Therefore it is possible to process a three-dimensional structure. This result should be applicable to functional optical devices. 相似文献
10.
D.M. Krol 《Journal of Non》2008,354(2-9):416-424
Tight focusing of ultrashort (~100 fs) infrared laser pulses of moderate energy (typically 1–10 μJ) into a glass results in very high, localized (in space and time) intensities, in excess of 1014 W/cm2. Under these conditions the laser–materials interaction becomes highly nonlinear, resulting in permanent modification of the material. By precisely controlling sample position and movement it is possible to optically ‘write’ three-dimensional patterns inside a glass. The modified glass can differ from the unmodified material in a wide variety of properties including refractive index, absorption coefficient, nonlinear optical susceptibility, crystal structure, morphology etc. In this paper, I discuss how ultrafast laser modification of glass can be used to add new functionality to glasses. The structures that can be fabricated with the ultrafast laser writing technique have applications in optical data storage, telecommunications and bio-sensing and -imaging. 相似文献
11.
SnO2 nanoparticles having an average particle size of 5 nm were precipitated in a transparent glass by irradiation with an 800 nm femtosecond laser. Glass was prepared to co-dope Sn4+ and Eu3+ ions by a sol–gel method, followed by heating in H2 gas atmosphere to form the Sn02 point defects with a molecular-like electronic structure in the twofold-coordinated Sn atoms. Upon laser irradiation, the Sn02 defects react with oxygen, forming SnO2 nanocrystals. When excited at the energy corresponding to the absorption edge of the SnO2 nanocrystals, the energies, which are absorbed by the quantum-dot effect in the nanosized crystals, are efficiently transferred to the Eu3+ ions, resulting in the large enhanced fluorescence intensities from the Eu3+ ions. The observed phenomenon suggests application to high-density memory devices. 相似文献
12.
The surface modification and crystallization process of BaO–B2O3–SiO2 glass compositions when exposed to CO2 laser irradiation was evaluated as a function of the laser power, irradiation time and surface condition. The glass surface was modified by the application of laser power exceeding 0.40 W and an irradiation time of more than 300 s. Micro-Raman and X-ray diffraction measurements revealed at high laser power the formation of β-BaB2O4 (β-BBO) crystalline phase. The crystallization of the irradiated region was enhanced when β-BBO micrometer sized particles were dispersed on the surface of the glass sample. The intensity of the second harmonic generation observed in the crystallized region was found to depend mainly on the condition of the glassy surface prior to glass irradiation. 相似文献
13.
M.S.B. Darby R.E. Simpson T.C. May-Smith D.W. Hewak R.W. Eason 《Journal of Non》2008,354(40-41):4582-4588
The influence of the deposition parameters on femtosecond and nanosecond pulsed laser deposited gallium lanthanum oxysulphide (GLSO) glass films has been investigated. A comparison between films deposited by femtosecond and nanosecond pulsed laser deposition (PLD) shows that the compositional range of each ablation regime varies significantly; in particular, femtosecond PLD shows a unique potential for selective fabrication of films with a high lanthanum content well outside the conventional glass-melting region. We demonstrate how manipulation of the PLD growth parameters can influence the stoichiometric transfer of the PLD process, leading to films with compositions that differ significantly from the GLSO target material. We also reveal how the refractive index of as-deposited films is dependent upon the composition and briefly discuss the thermal properties of bulk GLSO material of various compositions which indicate the potential for films grown by PLD to be used in optical data-storage device applications. 相似文献
14.
Koji Hatanaka Ken-ichiro Yomogihata Hiroshi Ono Kei Nagafuchi Hiroshi Fukumura Michiko Fukushima Tomohiro Hashimoto Saulius Juodkazis Hiroaki Misawa 《Journal of Non》2008,354(52-54):5485-5490
We have generated hard X-rays by front- and back-side femtosecond laser irradiation of PbO-rich glass. The actual Pb content of glasses was corroborated by Pb M-line emission intensities with an uncertainty of less than 20%. The elements K and As at concentrations of a few mol% were detected. X-ray generation by back-side irradiation helped to avoid an air breakdown; however, self-focusing and filamentation limited the achievable light intensity and effectiveness of X-ray generation. Characteristics and mechanisms of X-ray generation from the front- and back-side of glasses are discussed. 相似文献
15.
M. Lancry N. Groothoff S. Guizard W. Yang B. Poumellec P.G. Kazansky J. Canning 《Journal of Non》2009,355(18-21):1057-1061
The infrared femtosecond laser damage threshold is found to be independent of OH content in pure silica glass. Additionally, the density and the mean trapping time of electrons excited in the conduction band are also found to be independent on OH concentration. 相似文献
16.
Rapid synthesis of copper nanoparticles by sodium hypophosphite reduction in ethylene glycol under microwave irradiation 总被引:8,自引:0,他引:8
This paper presents a rapid method for preparation of copper metal nanoparticles by reducing CuSO4·5H2O with NaH2PO2·H2O in ethylene glycol under microwave irradiation. The influences of the reaction parameters, such as the concentrations of reducing agent and protective polymer time of microwave irradiation, on the size and agglomeration of copper nanoparticles were investigated by X-ray powder diffraction and transmission electron microscope. Well-dispersed copper nanoparticles with diameter of about 10 nm were obtained. The use of microwave irradiation accelerated the reaction rate and benefited the dispersion and the particle size distribution of the nanoparticles. 相似文献
17.
Fangfang Luo Geng Lin Huaihai Pan Qingxi Chen Jianrong Qiu Quanzhong Zhao Zhizhan Xu 《Journal of Non》2011,357(11-13):2384-2386
We report the elemental redistribution in a Bi-doped oxyfluoride glass induced by a 250-kHz femtosecond laser. Our results show that the relative concentration of the network modifier Bi ions in the modified region is higher than that in the unmodified regions. However, the relative concentration of the network modifier Ca ions is opposed to that of Bi ions. This is the first time to observe the differential distribution of relative concentration between the network modifiers. These results are important to practical application in the fabrication of waveguide lasers and amplifiers in active ion-doped glasses. 相似文献
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19.
We report on the characterization of structural modifications created by micro-explosions at the beam waist of a tightly focused femtosecond laser pulse inside of GeO2 glass. Micro-Raman scattering revealed the presence of structurally strongly modified regions at and around the irradiated sites. For separations of 5 μm between adjacent irradiated sites structural modifications due to a pressure increase are observed, whereas smaller spacings of 2 μm lead to thermal effects and crystallization. The mechanisms and the interplay of pressure and temperature effects are discussed. 相似文献
20.
Structural characteristics and optical properties of monometallic and bimetallic Ag and Au nanoparticles in the surface region of soda-lime glass fabricated by ion implantation have been studied by transmission electron microscopy and optical spectroscopy. As a result it has been found that both, implantation dose and process temperature, strongly influence the metal nanoparticle formation governed by ion diffusion and metal precipitation as well as the involved stress generation around the particles. Thus, the mean size of metal nanoparticles and the width of the particle containing region beneath the glass surface increase with increasing temperature as well as implanted dose. Upon sequential high-dose double implantation to form bimetallic Ag–Au nanoparticles a rather complex configuration has been obtained. Particles of sizes above a threshold of 5–10 nm exhibit distinct image contrast features indicating the development of central voids whose sizes are proportional to the outer particle diameter. 相似文献