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1
Content available remote Study on some linear and nonlinear optical parameters of glycine hydrofluoride single crystals
Abu El-Fadl A., Abdel-Salam A. M., Nashaat A. M.
Materials Science Poland
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2018
|
Vol. 36, No. 4
685--696
EN
Single crystal of glycine hydroflruoride (GHF) was grown from aqueous solution by slow evaporation technique. The structure of the grown crystal was tested and analyzed through X-ray powder diffraction. The functional groups have been identified from the FT-IR spectra. Slabs cut normal to the b-axis from the grown crystal were subjected to incident radiation with a wavelength range of 200 nm to 800 nm to investigate the transmittance and reflectance spectra. Linear optical parameters such as extinction coefficient k, refractive index n and both the real and imaginary parts: ∊real and ∊im of the dielectric permittivity were calculated as functions of the incident photon energy. The dispersion of the refractive index was fitted in terms of Cauchy formula and Wemple-DiDomenico single oscillator model. GHF crystals exhibited indirect optical interband transition and the optical energy gap Eg was determined by using Tauc plot. The indirect band gaps at elevated temperatures were determined and their temperature dependence was estimated. Optical band gap Eg values were found to decrease with an increase in crystal temperature; however, the band tail width exhibited opposite behavior. The nonlinear optical potential was examined by the second harmonic generation (SHG) test.
2
Content available remote Gas composition influence on the properties of boron-doped diamond films deposited on the fused silica
Dec B., Ficek M., Rycewicz M., Macewicz Ł., Gnyba M., Sawczak M., Sobaszek M., Bogdanowicz R.
Materials Science Poland
|
2018
|
Vol. 36, No. 2
288--296
EN
The main subject of this study are molecular structures and optical properties of boron-doped diamond films with [B]/[C]ppm ratio between 1000 and 10 000, fabricated in two molar ratios of CH4–H2 mixture (1 % and 4 %). Boron-doped diamond (BDD) film on the fused silica was presented as a conductive coating for optical and electronic purposes. The scanning electron microscopy images showed homogenous and polycrystalline surface morphology. The Raman spectroscopy confirmed the growth of sp3 diamond phase and sp2 carbon phase, both regular and amorphous, on the grain boundaries, as well as the efficiency of boron doping. The sp3/sp2 ratio was calculated using the Raman spectra deconvolution method. A high refractive index (in a range of 2.0 to 2.4 at λ = 550 nm) was achieved for BDD films deposited at 700 °C. The values of extinction coefficient were below 1.4 at λ = 550 nm, indicating low absorption of the film.
3
Content available remote Optical spectroscopic analysis of annealed Cd1−xZnxSe thin films deposited by close space sublimation technique
Ali I., Iqbal A., Mahmood A., Shah A., Zakria M., Ali A.
Materials Science Poland
|
2016
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Vol. 34, No. 4
828--833
EN
Cd1−xZnxSe (x = 0, 0.40 and 1) thin films were deposited on a glass substrate at room temperature by closed space sublimation method. Optical investigation has been performed using spectrophotometry and ellipsometry. It has been found that for as deposited films the optical band gap increased and the optical constants decreased with increasing Zn content. To improve the optical properties of Cd1−xZnxSe thin films annealing effect at 400 °C was taken into consideration for various Zn contents. It was observed that the optical transmittance and band gap decreased while optical constants increased with increasing Zn content after annealing. The effects of composition and annealing on the optical dispersion parameters Eo and Ed were investigated using a single effective oscillator model. The calculated value of the average excitation energy Eo obeys the empirical relation (Eo = Eg/2) obtained from the single oscillator model.
4
Content available remote The Optimization Problem in Spectroscopic Ellipsometry Technique : Optical Spectra Determination for Pb5Ge3O11 Crystal
Dorywalski K., Krzyżyński T.
Machine Dynamics Research
|
2015
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Vol. 39, No. 4
21-30
EN
Ellipsometric spectra Ψ(λ), ∆(λ) was measured for Pb₅Ge₃O₁₁ optical crystal in the spectral range 388-620 nm. Mathematical model was developed taking into account optical anisotropy and surface roughness of the measured specimen. Nonlinear regression method was applied in order to fit experimental and modeled data. Refractive index spectra no(λ) ne(λ) are determined for Pb₅Ge₃O₁₁ single crystal for ordinary and extraordinary light beams. Ellipsometric spectra Ψ(λ), ∆(λ) was measured for Pb₅Ge₃O₁₁ optical crystal in the spectral range 388-620 nm. Mathematical model was developed taking into account optical anisotropy and surface roughness of the measured specimen. Nonlinear regression method was applied in order to fit experimental and modeled data. Refractive index spectra no(λ) ne(λ) are determined for Pb₅Ge₃O₁₁ single crystal for ordinary and extraordinary light beams.
5
Content available Simple expressions for the designing of the double bandpass optical filter
Kushnir O.
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes
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2015
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Vol. 4, No 4
91--94
EN
Simple expressions for designing of the double bandpass optical filter have been obtained. These expressions make it possible to determine the phase thicknesses of the two symmetrical layers of multilayer structures, which provide double bandpass optical filter based on the interference reflector with an odd number of layers. The possibility of designing double bandpass optical filter with different bandwidth is shown.
6
Content available remote Determination of optical constants and thickness of amorphous GaP thin film
Pimpabute N., Burinprakhon T., Somkhunthot W.
Optica Applicata
|
2011
|
Vol. 41, nr 1
257--268
EN
Gallium phosphide (GaP) thin film was prepared by an asymmetric bipolar pulsed-dc magnetron sputtering technique onto glass substrate at room temperature in an Ar atmosphere. A compacted GaP powder was used as a target. The X-ray diffraction patterns show that the film is amorphous. The transmittance of the film was measured in the incident photon wavelength range of 300–2000 nm. The film’s refractive index, thickness and absorption coefficient as a function of wavelength were determined by using Swanepoel’s method. The deduced absorption data indicate that the optical transition in the film is dominated by the indirect type. The corresponding energy of 1.51 eV was obtained for the 563š16 nm thin film.
7
Content available Spectroscopic Ellipsometry Analysis of Rapid Thermal Annealing Effect on MBE Grown GaAs1-x-Nx
Sedrine N., Rihani J., Harmand J., Chtourou R.
Journal of Telecommunications and Information Technology
|
2009
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nr 1
51-56
EN
We report on the effect of rapid thermal annealing (RTA) on GaAs1-x-Nx layers, grown by molecular beam epitaxy (MBE), using room temperature spectroscopic ellipsometry (SE). A comparative study was carried out on a set of GaAs1-x-Nx as-grown and the RTA samples with small nitrogen content (x = 0.1%, 0.5% and 1.5%). Thanks to the standard critical point model parameterization of the GaAs1-x-Nx extracted dielectric functions, we have determined the RTA effect, and its nitrogen dependence. We have found that RTA affects more samples with high nitrogen content. In addition, RTA is found to decrease the E1 energy nitrogen blueshift and increase the broadening parameters of E1, E1+?1, E'0 and E2 critical points.
8
Content available remote Optical characterization of the CdZn(S1-x Sex )2 thin films deposited by spray pyrolysis method
Ilican S., Zor M., Caglar Y., Caglar M.
Optica Applicata
|
2006
|
Vol. 36, nr 1
29-37
EN
CdZn(S1-xSex )2 thin films have been deposited onto glass substrates by the spray pyrolysis method at a 275°C substrate temperature. The average optical transmittance of all the films was over 65% in the wavelength range 450-800 nm. The optical absorption studies reveal that the transition is direct with band gap energy values between 2.47-3.04 eV. The optical constants such as refractive index, extinction coefficient and dielectric constants have been calculated for these films. The dispersion parameters such as Eo (single-oscillator energy) and Ed (dispersive energy) have been discussed in terms of the Wemple-DiDomenico single-oscillator model. The values obtained by this method are suitable for many scientific studies and technological applications, such as gas sensors, heat mirrors, transparent electrodes, solar cells and piezoelectric devices.
9
Content available remote Refractive index dispersion and analysis of the optical constants of an ionomer thin film
Yakuphanoglu F., Erten H.
Optica Applicata
|
2005
|
Vol. 35, nr 4
969-976
EN
The basic optical properties and optical constants of the ionomer thin film have been investigated by means of transmittance and reflectance spectra. The real (n) and imaginary (k) parts of the complex refractive index and dielectric constant of the thin film were determined. The oscillator energy Eo, dispersion energy Ed and other parameters have been determined by the Wemple-DiDomenico method. The optical band gap Eg was determined and the optical absorption spectra show that the absorption mechanism is a direct transition. The most significant result of the present study is to determine optical constants and optical band gap of the thin film.
10
Content available remote Optical characterization of an amorphous organic thin film
Yakuphanoglu F., Sekerci M.
Optica Applicata
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2005
|
Vol. 35, nr 2
209-214
EN
The optical characteristics of Co(II) complex having 5,6-O-cyclohexylidene-1-amino-3-azahexane thin film were investigated by spectrometric measurements. The optical parameters, optical band gap Eg and width of localized states Ea of the film were determined using the transmittance T and the reflectance R at normal incidence in the spectral range 540-660 nm. The absorption edge of the film exhibits the exponential behavior which is attributed to the electronic transition in the localized states tailed off in the indirect energy band gap of the film. The refractive index spectra of the film show normal dispersion up to about 2 e V and afterwards, the refractive index increases with increasing photon energy.
11
Content available remote Optical properties of electron beam deposited lutetium oxide thin films
Wiktorczyk T
Optica Applicata
|
2001
|
Vol. 31, nr 1
83-92
EN
Lu/sub 2/O/sub 3/ thin-film coatings of a thickness 0.1-1.3 mu m were deposited onto quartz plates by an electron beam gun. Optical measurements were carried out for the wavelengths lambda =0.2 mu m-2.5 mu m. All fabricated coatings were highly transparent in the spectral range from 0.3 mu m to 2.5 mu m. Optical constants of Lu/sub 2/O/sub 3/ films have been determined from the spectrophotometrically measured transmittance. The dispersion n( lambda ) and extinction k( lambda ) curves in the spectral range considered have been presented and analysed. The refractive index for Lu/sub 2/O/sub 3/ films has been estimated as 1.84 at 0.55 mu m. The characteristics of the real and imaginary parts of the dielectric function epsilon *(v) are also presented. Values of epsilon '/sub infinity /=323-3.53 have been obtained as the high-frequency optical relative permittivity for Lu/sub 2/O/sub 3/ thin films.
12
Content available remote Ellipsometry in optical studies of thin films conducted at the Institute of Physics of Wroclaw University of Technology
Żukowska K., Oleszkiewicz E.
Optica Applicata
|
2001
|
Vol. 31, nr 1
35-51
EN
Ellipsometry is a very powerful and totally nondestructive technique for determining optical constants, film thickness in multilayered systems, surface and interfacial roughness and material microstructure. Ellipsometric measurements can be made in vacuum, air and other environments. Ellipsometry has traditionally been used to determine film thickness and optical constants of dielectrics and optical coatings, semiconductors and heterostructures, magneto-optic, magnetic and opto-electronic materials, electrochemical, biological and medical systems and in surface modifications and surface roughness investigations. In situ measurements during crystal growth or material deposition are useful to study constituent fractions (including void fractions) in deposited or grown materials, surface oxide formation and film growth kinetics. Ellipsometric studies of metal, dielectric, semiconductor and organic layers carried out at the Institute of Physics of Wroclaw University of Technology by members of Thin Films Group are presented.
13
Content available remote Determination of the thickness and optical constants of polyarylates with heterocyclic side chain group
Ratusznik G.J., Najechalski P., Ciolek R., Pura B., Zadrozna I., Mrozinski H.
Optica Applicata
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2001
|
Vol. 31, nr 1
103-114
EN
The investigation of the optical properties of the novel polyarylates with heterocyclic side chain groups is reported. Optical properties of the polymers obtained have been measured. Mechanical and thermal properties are also presented. The refractive index n( lambda ) and susceptibility chi /sup (1)/ have been determined for different compositions of polymers.
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