Optical Constant Determination of Thin Polymer Films in the Infrared

1985 ◽  
Vol 39 (3) ◽  
pp. 405-408 ◽  
Author(s):  
R. T. Graf ◽  
J. L. Koenig ◽  
H. Ishida
Keyword(s):  
Refractive Index ◽  
Optical Constant ◽  
Infrared Region ◽  
Transmission Spectra ◽  
Thin Polymer Films ◽  
Interference Fringes ◽  
Constant Determination ◽  
Thin Polymer ◽  
Good Agreement

Thin films of poly(vinyl chloride), poly(methyl methacrylate), and poly(styrene) were analyzed by Fourier transform infrared spectroscopy. The interference fringes present in the transmission spectra of these samples were used to determine film thickness and average refractive index. Subsequent Kramers-Kronig analysis of these transmission spectra provided the dispersion of the refractive index and the absorption index across the entire mid-infrared region. Interference fringes were absent in the optical constant spectra, and good agreement was obtained between our optical constant spectra and those of other authors.

DETERMINATION OF THE OPTICAL CONSTANTS AND THICKNESS OF SEMITRANSPARENT THIN FILMS USING SUCCESSIVE INTERFERENCE FRINGES OF TRANSMISSION SPECTRA

2005 ◽  
Vol 12 (03) ◽  
pp. 425-431 ◽  
Author(s):  
F. E. GHODSI
Keyword(s):  
Thin Films ◽  
Optical Constants ◽  
Optical Parameters ◽  
Transmission Spectra ◽  
Simple Method ◽  
Interference Fringes ◽  
True Values ◽  
Better Than ◽  
Good Agreement

A simple method for determination of optical constants and thickness of semitransparent thin films deposited onto a transparent finite substrate has been developed. The method is based on the analysis of successive interference fringes of transmission spectra created by the films. It is essentially not necessary to obtain the envelope of transmission spectra in this method. The determined values of optical parameters are in good agreement with their true values used to generate transmission data. The accuracy of method in determining refractive index and thickness of the films is better than 1%.

scholarly journals Size Determination of Polystyrene Sub-Microspheres Using Transmission Spectroscopy

2020 ◽  
Vol 10 (15) ◽  
pp. 5232
Author(s):  
Tien Van Nguyen ◽  
Linh The Pham ◽  
Khuyen Xuan Bui ◽  
Lien Ha Thi Nghiem ◽  
Nghia Trong Nguyen ◽  
...  
Keyword(s):  
Time Domain ◽  
Finite Difference Time Domain ◽  
Fdtd Simulation ◽  
Transmission Spectra ◽  
Experimental Transmission ◽  
Straightforward Method ◽  
Quartz Substrates ◽  
Difference Time ◽  
Good Agreement

Nano/micro polystyrene (PS) beads have found many applications in different fields spanning from drug delivery, bio-diagnostics, and hybrid plasmonics to advanced photonics. The sizes of the PS beads are an important parameter, especially in plasmonic and photonic experiments. In this work, we demonstrate a quick and straightforward method to estimate the diameters of sub-microspheres (0.2 μm to 0.8 μm) using the transmission spectra of a close-packed monolayer of polystyrene beads on glass or quartz substrates. Experimental transmission spectra of the PS monolayers were verified against finite-difference time-domain (FDTD) simulation and showed good agreement. The effects of the substrates on the transmission spectra and, hence, the accuracy of the method were also studied by simulation, which showed that common transparent substrates only cause minor deviation of the PS bead sizes calculated by the proposed method.

Determination of the flexural stiffness of thin plates from small deflection measurements using optical holography

1982 ◽  
Vol 17 (1) ◽  
pp. 53-61 ◽  
Author(s):  
M J Marchant ◽  
M B Snell
Keyword(s):  
Numerical Method ◽  
Accurate Determination ◽  
Metal Plate ◽  
Thin Plates ◽  
Flexural Stiffness ◽  
Interference Fringes ◽  
Small Deflection ◽  
Stiffness Properties ◽  
Good Agreement

A technique is presented for accurate determination of the flexural stiffness of thin plates using optical holography. Measurements of the interference fringes on thin rhombic plates in anticlastic bending are used to calculate the components of curvature by a simple numerical method Control experiments on a metal plate give good agreement with the results of small deflection bending theory. The method appears ideally suited to the measurement of anisotropic flexural stiffness properties.

scholarly journals Ultra-Narrow SPP Generation from Ag Grating

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 6993
Author(s):  
Gerald Stocker ◽  
Jasmin Spettel ◽  
Thang Duy Dao ◽  
Andreas Tortschanoff ◽  
Reyhaneh Jannesari ◽  
...  
Keyword(s):  
Refractive Index ◽  
Infrared Region ◽  
Spectral Shift ◽  
Experimental Results ◽  
Silicon Substrates ◽  
Signal Attenuation ◽  
Plasmonic Sensor ◽  
Quantum Cascade ◽  
Specular Reflectance ◽  
Good Agreement

In this study, we investigate the potential of one-dimensional plasmonic grating structures to serve as a platform for, e.g., sensitive refractive index sensing. This is achieved by comparing numerical simulations to experimental results with respect to the excitation of surface plasmon polaritons (SPPs) in the mid-infrared region. The samples, silver-coated poly-silicon gratings, cover different grating depths in the range of 50 nm–375 nm. This variation of the depth, at a fixed grating geometry, allows the active tuning of the bandwidth of the SPP resonance according to the requirements of particular applications. The experimental setup employs a tunable quantum cascade laser (QCL) and allows the retrieval of angle-resolved experimental wavelength spectra to characterize the wavelength and angle dependence of the SPP resonance of the specular reflectance. The experimental results are in good agreement with the simulations. As a tendency, shallower gratings reveal narrower SPP resonances in reflection. In particular, we report on 2.9 nm full width at half maximum (FWHM) at a wavelength of 4.12 µm and a signal attenuation of 21%. According to a numerical investigation with respect to a change of the refractive index of the dielectric above the grating structure, a spectral shift of 4122nmRIU can be expected, which translates to a figure of merit (FOM) of about 1421 RIU−1. The fabrication of the suggested structures is performed on eight-inch silicon substrates, entirely accomplished within an industrial fabrication environment using standard microfabrication processes. This in turn represents a decisive step towards plasmonic sensor technologies suitable for semiconductor mass-production.

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