Sellmeier Dispersion Formula Research Articles

Optical properties and the dispersion parameters of new zinc Phthalocyanine benzofuran derivative prepared by non-vacuum spin coating technique

The optical properties of 2(3),9(10),16(17),23(24)-tetrakis-{6-(-benzofuran-2-carboxylate)-hexylthio} phthalocyaninatozinc(II) {Zn[Pc(b-S(CH2)6OCOBz-furan)4], (ZnPcBzF) thin film prepared by spin coating method were investigated. The optical constants of the prepared film were determined using spectrophotometric measurements of the transmittance and reflectance at normal incidence in the spectral range 200–800nm. The analysis of the spectral behavior of the absorption coefficient in the intrinsic absorption region revealed two direct allowed optical band gap of 2.58 and 3.87eV. The dispersion of the refractive index was discussed in terms of the single oscillator using Sellmeier dispersion formula. The high frequency dielectric constant (ε∞) and the lattice dielectric constant (εL) were estimated. From the optical constants analysis, the optical conductivity was also considered. Discussion of the obtained results and their comparison with the previous published data were also given. The obtained results of this new zinc phthalocyanine benzofuran derivative (ZnPcBzF) support the desirable feature for the microelectronic and optoelectronic devices.

Sellmeier and thermo-optic dispersion formulas for CdSiP2

High-accuracy Sellmeier and thermo-optic dispersion formulas for CdSiP2 that reproduce excellently the temperature-dependent phase-matching conditions for the Tm:YALO and Nd:YAG laser-pumped optical parametric oscillator (OPO) are presented.

Absolute refractive index measurement method over a broad wavelength region based on white-light interferometry

We report a simple method of measuring the absolute values of the phase refractive index of an optical material of a flat plate shape over a wide spectral range at a single measurement run. A white-light interferometric technique with angle rotation of the optical plate sample located in one of the interferometer arms was used in this method. The validity of this method was proved by measuring the absolute phase refractive indices of flat plate samples of fused silica and BK7, and by comparing them with calculated values from their well-known Sellmeier dispersion formulas. The accuracy of this refractive index measurement method was within 0.002, which can be further improved by enhancing the angle measurement accuracy of the angle rotating stage used in this method.

Sellmeier and thermo-optic dispersion formulas for RbTiOPO 4

The thermo-optic constants for RbTiOPO 4 were measured from 20.0 to 120.0 °C in the 0.532–1.571 μm range. The Sellmeier and thermo-optic dispersion formulas that reproduce well the temperature-dependent phase-matching conditions for the normal and periodically poled crystals are presented.

Phase-matched pure χ^(3) third-harmonic generation in noncentrosymmetric BiB_3O_6

Third-harmonic generation (THG) has been investigated in the monoclinic BiB(3)O(6). The symmetry and birefringence analysis revealed that there are phase-matching conditions for the direct third-order nonlinear process, where the cascading second-order processes are precluded by the zero effective nonlinearity. The first phase-matched pure chi((3)) THG in a noncentrosymmetric crystal is presented together with the improved Sellmeier and thermo-optic dispersion formulas.

Optical properties of CuIn 5Se 8 and CuGa 5Se 8 from ellipsometric measurements

Spectroscopic ellipsometry measurements were done at room temperature on samples of CuIn 5Se 8 and CuGa 5Se 8. This allowed determining the real and imaginary parts of the complex refractive index N, the real and imaginary parts of the complex dielectric function ɛ, the absorption coefficient α and the reflectivity R. The energy gap values, E g, were obtained from fitting the numerically obtained second derivative, d 2 ɛ( ω)/d( ω) 2, of the experimental data, ɛ( ω), to analytic critical-point line shapes, and are in good agreement with those reported using other techniques. The value of the high frequency dielectric constant ɛ ∞ for each compound was determined fitting the real refractive index n to the Sellmeier dispersion formula.

Temperature phase-matching properties of mixed chalcopyrite AgGa1−xInxS2 crystal

AgGa1−xInxS2 with x=0.14±0.01 was found to be 90° phase-matchable for the second harmonic generation (SHG) of CO2 laser radiation at 10.591μm at 203°C. In addition, temperature-tuned 90° phase-matched difference frequency generation (DFG) at 4.02μm was demonstrated by mixing the idler output of a Nd:YAG third harmonic pumped β-BBO optical parametric oscillator and its fundamental source at 1.0642μm. The Sellmeier and thermo-optic dispersion formulas that reproduce well these experimental data are presented.

Measurement of the refractive index of distilled water from the near-infrared region to the ultraviolet region

By the minimum deviation method using a prism shaped cell, the absolute refractive indices of high-performance liquid chromatography distilled water were measured at the wavelengths from 1129 to 182 nm, at the temperature of 19 degrees C, 21.5 degrees C, and 24 degrees C, and then dn/dt at 21.5 degrees C was calculated. The coefficients of the four-term Sellmeier dispersion formula were determined by using the refractive indices at each temperature. As a result of the comparison of our refractive index data in the visible wavelength region with the formula by Tilton et al. at the National Bureau of Standards in 1938, both the refractive index data corresponded within 6 x 10(-6). In the UV region, the absolute refractive index at 193.39 nm calculated by the data measured nearby the wavelengths from 200 to 190 nm was 1.436517 (21.5 degrees C). The value was lower by 9 x 10(-5) or 10 x 10(-5) than the data measured by Burnett et al. at the National Institute of Standards and Technology.

Refractive‐index anisotropy and optical dispersion in films of deoxyribonucleic acid

AbstractWe have determined the refractive indices in the directions parallel and perpendicular to the surface plane of films of deoxyribonucleic acid (DNA) and their wavelength dispersion. These parameters are fundamental for understanding the properties of waveguiding structures containing DNA‐based photonic materials. The orientation of DNA molecules in films and their optical properties are sensitive to the film fabrication and environmental conditions influencing the structure. Prism coupling measurements show ambient‐humidity‐related changes in the refractive index, birefringence, and anisotropy of the alignment of the DNA molecules in the films studied. These films were 0.5–5 μm thick, were prepared by both spin coating and casting from aqueous solutions containing 0.1–3 wt % DNA, and were measured in ambient air with relative humidities of 37–58%. The optical properties of the films and the orientation of the DNA molecules are discussed with respect to the mechanism for the formation of the polymer liquid‐crystalline phases during film deposition. The dispersion of the refractive indices in films of native DNA has been derived from interference fringes in absorption and reflection spectra in the wavelength range of 350–2700 nm through the fitting of the positions of the fringes with the Sellmeier dispersion formula in combination with the prism coupling data. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 236–245, 2007

New data on the optical properties of BiB3O6

New Sellmeier and thermo-optic dispersion formulas for BiB3O6 that reproduce well the nonlinear experimental results in the 0.4740–3.083μm range are presented.

Parametric oscillation at 2.1 μm in periodically poled RbTiOAsO4

An Nd:YAG laser-pumped periodically poled RbTiOAsO4 (PPRTA) optical parametric oscillator (OPO) near degeneracy is reported. At a pump power of 3.7W, a net conversion efficiency of 43% was obtained. These crystals were found to be phase-matchable for the higher order quasi-phase-matched second-harmonic generation (SHG) in the visible range. Detailed analyses of the phase-matching properties for these processes were made by using the published Sellmeier and thermo-optic dispersion formulas.

High-accuracy measurements of the refractive index and its temperature coefficient of calcium fluoride in a wide wavelength range from 138 to 2326 nm

The refractive indices of synthetic calcium fluoride for 69 wavelengths from 138 nm in the deep ultraviolet to 2326 nm in the near infrared were measured by the minimum-deviation method in a nitrogen environment. We made these measurements at 20 degrees and 25 degrees C, respectively, to determine the thermal coefficients of the refractive index over this wide-wavelength region. These refractive indices were fitted to a four-term Sellmeier dispersion formula. The temperature coefficients of the refractive index were fitted to a Hoffman-type dispersion formula. The standard deviation of the residual between the observed values and the calculated values was 0.6 x 10(-6) for the refractive index and was 0.13 x 10(-6)/degrees C for the temperature coefficient of the refractive index.

Sellmeier and thermo-optic dispersion formulas for KTP.

KTP has been found to be phase matchable for type-2 second-harmonic generation of the third harmonics of the CO2 laser wavelengths at 9.2714 and 9.5525 microm at 20.0 degrees C. The resulting angle and temperature-tuning data combined with the literature values of the Nd:YAG laser-pumped optical parametric oscillator were used to improve the Sellmeier equations and the thermo-optic dispersion formula that reproduce well the temperature-tuned 90 degree phase-matching conditions of the flux-grown crystals. Applications to quasi phase matching are presented.

Interferometric determination of refraction and dispersion of a birefringent material: numerical procedure

Air, liquid and solid sample interferometric gaps of the same thickness and simultaneously enclosed in a wedge interferometer are used to produce fringes of equal chromatic order. A mica sample of dimensions 2×5 mm 2 and an immersion liquid of the same refractive index are used. A single shot interferogram containing fringes in the three gaps is sufficient to deduce the needed experimental data. Locations of fringe maxima are introduced in a numerical procedure to retrieve the sample and liquid refractive indices across the visible spectrum. The numerical procedure is based on a simple dispersion function of wavelength and wavenumber. A modified two-term Sellmeier dispersion formula has been used for fitting the experimental data and deducing the needed dispersion parameters.

Measurement of AlxGa1-xN Refractive Indices

Dispersion of the ordinary and extraordinary indices of refraction have been measured systematically for wurtzitic Al x Ga 1-x N epitaxial layers with 0 ≤ x ≤ 1.0 throughout the visible wavelength region 457 nm < λ < 800 nm. The dispersion, measured by a prism coupling waveguide technique is found to be well described by a first-order Sellmeier dispersion formula parameterized as functions of x and λ.

Interferometric determination of refraction and dispersion of a birefringent material: non-numerical procedure

Fringes of equal chromatic order are produced in air, immersion liquid and mica sample interferometric gaps. The three gaps are of the same thickness and simultaneously enclosed in a wedge interferometer. A single-shot interferogram contains fringes in the three gaps is sufficient to deduce the needed experimental data. A non-numerical procedure is used for determining the refractive indices of the immersion liquid and mica sample across the visible spectrum. There is no need for any numerical fitting stage nor for the application of any theoretical model concerning the dispersion behavior of the sample under test. A modified two-term Sellmeier dispersion formula has been used for fitting the experimental data and deducing the needed dispersion parameters.

Generation and healing behavior of radiation-induced optical absorption in fluoride phosphate glasses: The dependence on UV radiation sources and temperature

High purity fluoride phosphate (FP) glasses have a large transmission range from the vacuum ultraviolet to the infrared. They are attractive candidates for lens systems in microlithography equipment and excimer laser optics. Fluoride single crystals and vitreous silica are well-known traditional materials for ultraviolet optics. Crystal sizes are limited and glass is better for fabricating optics. For lens systems, a variety of glasses with different refractive indices and dispersion are required. The UV resonance wavelengths of FP glasses with a low content of phosphate using a two-term Sellmeier dispersion formula are comparable with those of silica and fluoride single crystals. It is known, that UV radiation induces the generation of several defect centers leading to additional absorption bands. The investigation of the kinetics of defect generation is very important for the prediction of transmission losses in case of long-time irradiation. To predict the kinetics of defect generation, first the separation of absorption bands is necessary. Experiments were carried out using UV-lamps, the KrF excimer laser (ns- and fs-pulses) and the ArF excimer laser (ns-pulses). The healing behavior of radiation-induced absorption bands was investigated using thermal treatment (temperature-dependence) and bleaching experiments (radiation-dependence). The results of these experiments enable the separation of absorption bands and the prediction of the defect generation depending on the used radiation source. The healing of strong defects at room temperature is postulated to be a diffusion-controlled process.

Electric potential energy of the incident light and the Hamiltonian of the induced oscillators in non-absorbing isotropic dielectrics

By considering an energy balance between the electric potential energy of the incident light and the Hamiltonian of the induced oscillators in a non-absorbing isotropic medium, the Newton–Drude equation, the Sellmeier dispersion formula, and the wavelength-dependent mean polarizability were derived. The Newton–Drude formula and the Lorentz–Lorenz equation were used to calculate the density-dependent mean polarizability of the densified silica glasses. The evaluated mean polarizability was compared with the band shifts in the UV- and IR-spectra with the density of glasses, and the validity of the Newton–Drude formula was discussed.

Ordinary and extraordinary refractive indices for AlxGa1−xN epitaxial layers

Dispersion of the ordinary and extraordinary indices of refraction for wurtzite AlxGa1−xN epitaxial layers with x=0.00, 0.04, 0.08, 0.11, and 0.20 in the range of wavelengths 457&amp;lt;λ&amp;lt;980 nm were measured via a prism-coupled waveguide technique. The quantitative accuracy of x is ±10% and the accuracy of the refractive indices is ∼±0.01. The dispersion is found to be well described by a 1st-order Sellmeier dispersion formula. A simple functional form is presented that allows calculation of the refractive indices as functions of x and λ.

Application of multiple-beam white-light fringes for measuring the refraction and dispersion of mica

Multiple-beam white-light interference fringes are applied to measure the two refractive indices of a mica sample and their dispersion across the visible spectrum. In addition, the mica birefringence and its dispersion are measured. A mica sample of dimensions 2 x 5 mm 2 and an immersion liquid of nearly the same refractive index are used. Only a single shot interferogram is needed to measure all the aforementioned parameters. Cauchy's and a modified single-term Sellmeier dispersion formula are used for fitting the experimental data and extracting the parameters required.