- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Laser-stimulated birefringence of Ga2O3-La2S2.95Se0.05 glasses for optical recording of information
摘要： We show an opportunity to change the birefringence of Ga2O3 – La2S2.95Se0.05 glasses doped by Er3+ and La3+ ions at λ = 1150 nm wavelength of cw He-Ne laser under illumination of the femtosecond laser. The variation of the refractive indices was found during illumination by 180 fs laser with frequency about 65 MHz (at wavelength λ = 1045 nm). The laser-stimulated birefringence has been explored versus temperature. The observed laser induced and temperature dependences of the birefringence con?rm a huge contribution of anharmonic phonon subsystems which is typical for chalcogenide glasses. Due to an occurrence of local space charge density asymmetry, the e?ciency of birefringence is enhanced. The anisotropy e?ect exists only during the illumination and is diminished during 10…12 s after switching o? of the photo-inducing laser treatment. There is observed also a correlation between the occurred grating patterns and the values of the birefringence.
关键词： Chalcogenide glasses,Optoelectronic materials,Laser-induced e?ects,Birefringence,Electronic and electrical engineering
更新于2025-09-19 17:13:59
-
Controlled nanoa??crystallization of IR frequencya??doubling Cd <sub/>4</sub> GeS <sub/>6</sub> crystal in chalcogenide glass
摘要： Crystallization of IR frequency-doubling nanocrystals in chalcogenide glasses is a promising approach to achieve novel nonlinear optical materials. However, controllable glass crystallization remains challenging. In this study, IR-transparent chalcogenide glass-ceramics containing novel Cd4GeS6 IR frequency-doubling na- nocrystals (about 60-80?nm) are fabricated through controlled nano-crystallization. Nanocrystalline structure of the Cd4GeS6 nano-crystallized glass-ceramics is inves- tigated in detail through X-ray diffractometer, field emission scanning electron mi- croscope, and Raman scattering techniques. The structural similarity of [Cd4GeS6] polyhedron in the network structure of as-prepared glass is found to be responsible for the nucleation of Cd4GeS6 crystal. A unique microstructure of Cd4GeS6 nanocrys- tals embedded GeS2 phase-separated structure is discovered in samples thermally treated at high temperatures (370°C and 380°C). This study would not only shed more light on glass crystallization mechanism but also provide a feasible approach for the design and fabrication of new IR frequency-doubling materials through glass crystallization.
关键词： Cd4GeS6,microstructure,glass-ceramics,chalcogenide glasses,crystallization
更新于2025-09-19 17:13:59
-
[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - In Situ Fabrication of Far-Detuned Mid-Infrared Optical Fiber Wavelength Converters
摘要： In Situ Fabrication of Far-Detuned Mid-Infrared Optical Fiber Wavelength Converters. Chalcogenide (ChG) glasses have been identified as promising materials for applications in nonlinear photonics due to their exceptionally high nonlinear refractive index; nearly three orders of magnitude beyond that of silica glass. A ChG fiber or waveguide that is tapered down into a microwire provides strong light confinement and enhanced nonlinear optical effect, it allows engineerable chromatic dispersion and thereby an easy access to nonlinear parametric processes such as four-wave mixing (FWM). In well-controlled conditions of chromatic dispersion ChG microwires may lead to strong parametric gain that is far-detuned with respect to the pump wavelength, by tens of THz [1,2]. In theory, chromatic dispersion in a waveguide is precisely adjusted from a good control of waveguide geometry. In practice however, the amount of precision required in waveguide geometry as well as errors on the evaluation of refractive indices prevent the fabrication of wavelength converters with a predetermined wavelength offset. To illustrate this, fig. 1(a) shows the theoretical spectrum of a far-detuned ChG wavelength converter. A change in the core diameter by 5 nm results in a ~ 40 nm wavelength shift of the parametric sidebands. As an element of solution inspired from past reports, it has been shown with supercontinuum generation that experimental parameters could be finely tuned using an in situ monitoring technique [3]. In this work, we demonstrate that wavelength conversion of a ChG microwire is precisely attained by in situ tracking of the microwire output during the tapering process, enabling the fabrication of wavelength converters that are precisely far-detuned by at least 34.3 THz.
关键词： four-wave mixing,nonlinear photonics,in situ tapering,Chalcogenide glasses,wavelength conversion
更新于2025-09-16 10:30:52
-
Investigations of physical parameters of Ge doped binary Se-As chalcogenide glassy alloys for optical fiber application
摘要： Germanium doped chalcogenide glasses have potential applications in non- linear and optoelectronic devices. Ternary Ge-Se-As system has been considered to study the different important physical parameters. The impact of deviation of Ge on the cost of As in Ge-Se-As glassy system has been discussed in terms of average coordination number, cohesive energy, heat of atomization, and the theoretical optical band gap of the system. Almost all the physical parameters are found to change linearly with the variation in Ge content. The physical properties approximated in the present study can reveal the structural details for optical fibers.
关键词： Chalcogenide glasses,cohesive energy,mean bond energy,glass transition temperature,lone pair electrons
更新于2025-09-16 10:30:52
-
Laser-induced optically modified Se <sub/>58</sub> Ge <sub/>27</sub> Pb <sub/>15</sub> and Se <sub/>58</sub> Ge <sub/>24</sub> Pb <sub/>18</sub> thin films
摘要： Amorphous samples of Se58Ge27Pb15 and Se58Ge24Pb18 glasses were prepared using the melt quenching method. Thin films of samples were deposited using the vacuum evaporation method. These films were illuminated with Nd: YAG 532 nm green laser radiation. The samples were structurally characterised using X-ray Diffraction (XRD) and Energy-dispersive X-ray analysis. XRD indicated an increase in the crystallinity of samples on laser irradiation. The samples were optically tested through absorption, reflection and transmission spectra recorded on UV-vis spectrophotometer. The obtained values of energy band gap, refractive index, extinction coefficient and Urbach energy of the films were compared both before and after laser exposure. Furthermore, it was found that sample thickness also changes on laser irradiation. The band gap of the samples was found to decrease laser irradiation in Se58Ge27Pb15thin films, while for Se58Ge24Pb18 thin film samples, an unexpected increase in band gap was observed at a laser irradiation time of 8 min. The variable behaviour of band gap has been explained on the basis of Mott and Davis model and heteropolar bond formation.
关键词： thin films,laser irradiation,Chalcogenide glasses,optical properties
更新于2025-09-12 10:27:22
-
Femtosecond laser-induced large area of periodic structures on chalcogenide glass via twice laser direct-writing scanning process
摘要： We presented a theoretical and experimental study for the evolution of femtosecond laser direct-writing induced large area of periodic surface structures on As2S3 glass. The laser direct-writing induced large area of low spatial frequency LIPSS (LSFL) structures can be fabricated with the overlap rate increases from 65% to 80%. The evolution process can be defined by the competition between the laser fluence and pulse overlap rate. What is more important is that, based on secondary femtosecond laser scanning process, the interaction between the initial LSFL structures induced by the first scanning and the laser pulse of the second scanning process can induce local field enhancement effect, which can directly split the surface periodic structures of LSFL. Such new sub-sequent high spatial frequency LIPSS (HSFL) fabrication process is quite different from the traditional multi-pulse induced HSFL and can be used to fabricate large-area HSFL structures.
关键词： Nano-fabrication,Femtosecond laser,LIPSS,Chalcogenide glasses
更新于2025-09-11 14:15:04
-
[IEEE 2019 21st International Conference on Transparent Optical Networks (ICTON) - Angers, France (2019.7.9-2019.7.13)] 2019 21st International Conference on Transparent Optical Networks (ICTON) - Direct Laser Writing Using Chalcogenide Thin Films
摘要： Direct laser writing has been performed in thin AMTIR-1 layers. By using 10 ns laser pulses, 250 nm thick lines have been written by tightly focusing the laser beam on the thin film layers. The possibility to enhance this resolution by using the Sb2Te3 material as super-resolution mask is also discussed.
关键词： saturable absorption,direct laser writing,Z-scan,super-resolution,nonlinear optics,chalcogenide glasses
更新于2025-09-11 14:15:04
-
[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Polarization Dependance Engineering of Chalcogenide Optical Fiber Couplers
摘要： Chalcogenide (ChG) glasses are well known as key materials for the fabrication of optical fiber components compatible with optical transmission in the mid-infrared. Recently, single-mode ChG optical fiber couplers (OFCs) have been proposed for broadband coupling as well as for wavelength multi/demultiplexing [1]. From silica fibers, it has been shown that a proper engineering of fused optical fiber couplers can lead to polarization beamsplitting [2]. Here, we explore the polarization properties of single-mode OFCs made out of ChG glass. We show that by an appropriate engineering of their aspect ratio, the polarization dependence of OFCs is adjusted from highly polarization dependent down to polarization independent.
关键词： mid-infrared,polarization dependence,aspect ratio,Chalcogenide glasses,optical fiber couplers
更新于2025-09-11 14:15:04
-
Study of the optical properties of amorphous As–Se–S thin films
摘要： This study investigates the effects of substitution of selenium by sulfur on the optical constants of amorphous (a-)As20Se80 ? xSx films (x = 0, 4, 8, 12, 16, and 20 at%), where the coordination number for both Se and S is the same. The absorption coefficient, α, and the index of refraction, n, were derived using the transmission spectra in a wide range of wavelengths from 400 to 2500 nm. This revealed that the index of refraction for the a-As20Se80 ? xSx system decreases with increase in sulfur content throughout the range under study. The effective coordination number of As has been determined based on the refractive index dispersion analysis. A decreasing in Nc from 4.022 to 3.752 with increase content of sulfur from 0 to 20 at% has been recorded. In addition, the optical bandgap, Eg, of the a-As20Se80 ? xSx thin films increases with increase in S content which can be explicated in terms of the chemical bond approach.
关键词： optical bandgap,refractive index,amorphous As–Se–S thin films,chalcogenide glasses,optical properties
更新于2025-09-10 09:29:36
-
Study of dielectric relaxation and thermally activated a.c. conduction in multicomponent Ge10-xSe60Te30Inx (0 ≤ x ≤ 6) chalcogenide glasses using CBH model
摘要： Amorphous Ge10-xSe60Te30Inx (0 ≤ x ≤ 6) chalcogenide glasses were prepared by melt quench technique. Surface morphology with the chemical composition of the prepared glass was examined using SEM and EDS analysis respectively. Dielectric properties and a.c. conductivity of the multicomponent Ge10-xSe60Te30Inx (0 ≤ x ≤ 6) chalcogenide glasses have been examined in the frequency range 100Hz to 1MHz and temperature range 303 to 328K. It was noticed that dielectric constant and dielectric loss decreases with the increase of frequency and increases with the increase of temperatures. Frequency and temperature dependence of dielectric constant was explained by orientational polarization. The variation of dielectric loss with frequency and temperature was explained by conduction loss and theory of single polaron hopping of charge carriers suggested by Elliot and Shimakawa for chalcogenide glasses. The experimental results show that a.c. conductivity follows the power law where s<1 and value of s decreases with the increase of temperature. The present findings of a.c. conductivity and variation of s with temperatures are reasonably well interpreted in terms of CBH model.
关键词： a c conductivity,dielectric relaxation,Chalcogenide glasses,CBH model,activation energy.
更新于2025-09-10 09:29:36