Search

•Doping Mn4+leads to an increase in the lattice constant of K2SiF6.•Mn4+doping causes alterations in the energy band structure of K2SiF6.•Doping with Mn4+enhances the absorption of visible light in K2SiF6.

Hybrid metal-dielectric guided mode resonance devices have an advantage over the all-dielectric guided mode resonance device for having a thin metal grating conductive layer that can be used as an electrode for tunable applications. In this work, we investigate the coupling between the waveguide mode and surface plasmons of the gold nanoslits grating in the hybrid guided mode resonance filter. It is shown that the coupling between the waveguide mode and surface plasmons can be engineered by increasing either the thickness of the low index of the refraction spacing layer or the thickness of the high index of the refraction waveguide layer. Therefore, a narrow spectral linewidth and a high finesse of hybrid guided mode resonance filters can be obtained by increasing the thickness of the low index of the refraction spacing layer or the thickness of the high index of the refraction waveguide layer. A hybrid guided mode resonance transmission filter with a narrow spectral linewidth of 2.8 nm is designed at the 1660.2 nm center wavelength.

We propose an accurate and rapid azimuth calibration method for polarizing elements in ellipsometry. Over 200 calibrations were achieved simultaneously at different wavelength points in a spectral range of 550–650 nm without any calibrated element. The azimuth of the polarizer was determined from the differential spectral analysis on the ellipse azimuth of reflected light. The information of the ellipse azimuth is experimentally acquired in the spectral range by a rotating polarizing element and a spectrometer. The presented method was performed and verified with Si and Au bulk, respectively, showing reliability and feasibility for efficient and reliable calibration in ellipsometry.

Silver (Ag) films with different nanostructures were prepared by electron beam evaporation and characterized by spectroscopic ellipsometry in combination with X-ray diffraction and field emission scanning electron microscopy (FESEM). The percolation threshold and the nanostructures of Ag films can be deduced from the measured ellipsometric parameters (Ψ, Δ). According to the different topological properties of (Ψ, Δ) trajectories, the percolation threshold of Ag films was determined to lie between the coverage of 66 and 79.6%. The result was further confirmed by the plus–minus sign of the real part of the dielectric function in the infrared. Silver particles, coalescence, networks, and continuous nanostructures were clearly identified from the topological properties of the tangent azimuth of (Ψ, Δ) trajectories, which were verified by the FESEM results. This work is useful for monitoring the fabrication of nanostructure materials in the industry and research field. In addition, it has potential applications on the recognition of micro–nanostructures in the artificial intelligence field.

In this paper, we investigate a new, to the best of our knowledge, type of guided-mode resonance optical filter with polarization-independence at normal incidence and relatively narrow spectral linewidth in the near-infrared regime. The new optical spectral filter consists of a 2D array of silicon nanorings on silicon film on silica substrate. Using finite difference time domain (FDTD) simulations, it is found that the spectral linewidth of the optical filter is primarily controlled by nanoring width and is tolerant to the variations of the size and height of silicon nanorings. FDTD simulations also reveal that the excited guided mode is more tightly confined in the nanoring structures with smaller ring widths. It is explained that the narrow spectral linewidth of the nanoring structure filter is due to the smaller scattering cross-section of the silicon nanorings and tighter confinement of the guided mode. Our optimally designed optical reflection filter exhibits a 2.4 nm spectral linewidth with nearly 100% peak reflectance at the resonance wavelength.

The melting and deflagration of nanometer indium particle thin films with an average diameter of 43.2 nm were characterized by temperature-dependent ellipsometry. During ellipsometric measurement, the sample temperature varied from room temperature to 270 °C. Two sharp breakpoints in the temperature-dependent curves of ellipsometric parameters were found at 155 and 251 °C, respectively. The former sharp breakpoint at 155 °C is ascribed to a physical phase change from solid to liquid, and the later one at 251 °C is due to the chemical phase change from liquid indium to solid indium oxide. The temperature of 251 °C is just the deflagration point of liquid indium particles, which was observed with temperature-dependent ellipsometric measurement for the first time. The results given by ellipsometry were further confirmed by conventional measurements of differential scanning calorimeter, thermogravimetric analysis, and X-ray diffraction. Compared with conventional measurements, the ellipsometric method is more sensitive and effective.

•α- and β-Te transform into each other under certain biaxial strains.•α- and γ-Te possess indirect band gaps whereas β-Te has a direct band gap.•The band gap values approach zero at a large strain regime for all systems.•Lower effective masses can be obtained by applying strain in monolayer Te.

Size-dependent melting properties of nanometer-sized Indium particles with size ranging from 25.5 to 68.1 nm were studied by spectroscopic ellipsometry, and a critical size is found between 42.4 and 44.9 nm. The melting points of nanometer-sized Indium particles with size larger than critical size are almost the same as that of bulk indium, while no clear melting point was found for indium particles with size smaller than the critical size. A knee point defined as the average melting point was introduced to characterize the melting of these smaller size particles, and it depresses with decreasing size. The mechanism for size dependent melting of indium particles was discussed. This work shows that spectroscopic ellipsometry is an effective optical tool for characterizing the melting of nanometer-sized metal particles.

In1–xSnx(x= 0.06–0.51) alloy films were deposited on Si substrates by electron beam evaporation and characterized by X-ray diffraction, field-emission scanning electron microscopy, atomic force microscopy, and spectroscopic ellipsometry. The dielectric functions of the In1–xSnxalloy films were obtained in the energy range from 1.55 to 4.13 eV based on the spectroscopic ellipsometry measurements, and it is believed that a solid–solid phase transitions led to changes in ε. The phase diagram of nanometer-sized particles is different from that of the bulk material, and this phenomenon can be explained by the surface stress of the particles. The effects of alloying on the electronic band structure were studied from the perspective of first-principles calculations.

The optical matrix method and finite element method were applied to analyze the thermal response of a typical double-recording-layered magneto-optical (MO) disk exposed with laser beams in the blue band. The MO disk with GaP as interlayer has the advantage of generating a larger difference in Joule loss density and temperature profile at two blue wavelengths compared with the MO disk with SiN as interlayer. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The effect of Ni content, film thickness, Ar pressure upon the magnetic and magneto-optical (MO) properties are studied with the (CoPt3)1−xNix(x=0–0.5) alloy films. Experimental data indicate that Ar pressure greatly affect the Kerr rotation angle during the blue-wave range. For the studied (CoPt3)1−xNixalloy films, the satisfactory thickness for obtaining large perpendicular magnetic anisotropy is 42 nm. During the red-wave range, Ni addition almost has no effect on the potential figure of merit (PFOM), however, Ni addition (x≈0.5) may induce satisfactory perpendicular anisotropy and coercivity. Although Ni addition reduces the Curie temperature, it also reduces the PFOM in the blue-wave range.

Pronounced spin precessions are observed in Fe films grown on n-doped GaAs(001) with a tailored Schottky interface under low-energy ultrafast laser excitation, more than two orders of magnitude smaller than typically required in heat-induced excitation. Pump wavelength dependence of the precession amplitude shows that the fast drift of the optically excited free carriers in the narrow depletion layer of GaAs is the key mechanism to generate the significant transient magnetic field triggering spin precessions.

Using e-beam evaporation, the ellipsometric parameters of thick transparent films are studied with the modified analysis method for the SiO2 film samples deposited onto the Si substrate. The ellipsometric parameters are measured at the incidence angles changing from 50? to 70? and in the 3-4.5 eV photon energy range. The error in the conventional method can be significantly reduced by the modified ellipsometric method considering the spatial effect to show good agreement between the theoretical and experimental results. The new method presented in this letter can be applied to other optical measurement of the periodic or non-periodic film structures.