tan_1998

C. Z. Tan, “Determination of refractive index of silica glass for infrared wavelengths by IR spectroscopy”, J. Non-Cryst. Solids 223, 158 (1998)

Source record · Catalogue · Review register

DOI: 10.1016/s0022-3093(97)00438-9

Source kind: measurement

Recorded technique: Channelled-spectrum (Fabry-Perot fringe) interferometry in an FT-IR transmission spectrum: a silica-glass disk (Suprasil 2, ~1000 ppm OH), 15 mm diameter, 230 um thick (gauge, +-1 um; thickness variation within 2 um), both faces polished, Perkin Elmer System 2000 FT-IR, 1000 scans, 4 cm-1 resolution. n at each transmission maximum from n(lambda_(m-i)) = (m - i) lambda_(m-i)/(2h) (Eq. 6), the order fixed by the fringe at lambda_m = 3.1174 um, where Malitson’s Eq. (1) gives the order m = 209 (pp. 160-162).

Materials in structured entries: None recorded.

Dataset quantities: None recorded.

Contents: 0 datasets; 0 formulas.

Curation notes

Pages 158-163 are pdf pages 1-6. Identity checked against the first page. Nothing is tabulated: the measured indices, 3-6.7 um, are shown only in Fig. 5 (open circles, with Malitson’s Eq. (1) as the curve; figure not digitised), so the record has no datasets. Fig. 3 is the 230-um plate’s transmission spectrum (OH band at 3672 cm-1, CO2 on the surface at 2350 and 2393 cm-1, OH and water bands at 2259-1632 cm-1); Fig. 4 typical fringes; Figs. 1-2 schematics.

WHAT THE TEXT STATES. Fringes are seen from 3 to 6.7 um except in the CO2 bands and at 4.7-5 um, where the missing fringes are counted from the fringe spacing; they vanish at 7.08-7.4 um (where n from Kramers-Kronig analysis approaches 1) and reappear beyond 7.4 um, where the method is not applied (p. 162). ‘In the overlapping region [3-3.7 um], the error of the evaluated refractive indices is found to be within +-0.0005’; ‘the accuracy for determination of refractive index can approach ~10^-3’ (+-1 um in the thickness), the experimental error ‘(~+-10^-3)’ (pp. 162-163). ‘For silica glass, the evaluated refractive indices in the investigated wavelength region are exactly equal to the extrapolation results of Eq. (1)’ (p. 162): the evidence refractiveindex.info cites for using Malitson’s formula to 6.7 um. The OH content (~1000 ppm) and sample preparation are argued to be negligible at this accuracy (Eqs. 9-10, p. 163).

FORMULA. Eq. (1) is Malitson’s three-term Sellmeier equation reproduced (coefficients identical to malitson_1965/sellmeier, with the range printed 0.213856-3.7067 um); it is not recorded again. The reference to Malitson is printed ‘J. Opt. Soc. Am. 53 (1965) 1205’ (volume 55).

Recorded bibliographic identity status: VALIDATED_WITH_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents.

Datasets

No datasets are recorded.

Formulas

No formulas are recorded.

Corrections

No dataset errata are recorded in this source record.

Formula corrections, where recorded, appear with their formulas above. Curation notes may also discuss corrections or unresolved interpretation. Consult the review register for the checks and decisions.