Calculation of the optical constants of a thin layer upon a transparent substrate from the reflection spectrum using a genetic algorithm

Extraction of infrared optical constants from fringing reflectance spectra

“…The angle difference D/ is p between two nearest oscillating peaks in the weak absorption region according to Eqs. (3) and (8).…”

“…[1][2][3] For a slab of weak optical absorption, one usually considers only the real part of the index (called the refractive index) and neglects the imaginary part (called the extinction coefficient) for simplicity in analysis. 2,[4][5][6][7][8][9] However, the latter becomes important when a more accurate analysis is required. 2 It can reveal spectral features behind which there are interesting physical processes.…”

Advanced Computer Drawing Envelopes of Transmittance Spectra of Thin Film Specimens

“…Such tangential points though occur only in the spectral region of negligible to medium absorption in the film [6], which limits the spectral region of applicability of the algorithm. Nevertheless, this algorithm is often-used for drawing envelopes of transmittance spectra, in optical characterization by the method of Swanepoel [10][11]. Furthermore, in [9] are shown computed data for n(λ = 300÷700 nm) of a film (Y 2 O 3 ) 0.9 :(SiO 2 ) 0.1 of the rare earth element Ittrium.…”

Measurement method for high-temperature infrared optical constants of ZnS crystal materials in a multi-layer structure

“…The spectrophotometric method was wildly used to determine the optical constants of thin films from the reflectance and transmittance measurements based on the minimization process of the difference between the calculated and the measured values [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23], or based on the interference fringe patterns process [24][25][26][27][28][29][30]. And various combinations of measured quantities at various conditions (the transmittance, the reflectance from the front or back side, the normal or oblique or multiple angles incidence, the perpendicular or parallel polarized radiation) can be used.…”