|Optical Homogeneity Guaranteed(×10-6)||Deviation of|
a single lot
| ||>Explanation For Table of i-Line Glasses|
|>Catalog data (Excel Form 135KB) April 28, 2017
|| Refractive index is calculated from dispersion formula. 6th decimal place will be rounded up when we show refractive index with 5 decimal places and 7th decimal place will be rounded up when we show refractive index with 6 decimal places.
|(Notice)||Optical Homogeneity Guaranteed : Please consult us if you need tighter specification. In case the thickness of the material is 25mm or less, we will guarantee the Optical Homogeneity by measurement using 25mm or more thick material.|
|(Notice)||Tolerance of Refractive Index: Please consult us if you need tighter specification.|
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i Line List
Internal Transmittance (τi)
Internal transmittance of the glass is indicated as guaranteed minimum transmittance at 365nm (10 and 25 mm sample thickness). Please note this is internal transmittance, reflection losses are not included.
The degree of solarization is indicated as a decrease in transmittance caused by radiation from a super high pressure mercury-vapor lamp. The detailed measurement method is described in the "Japanese Optical Glass Industrial Standard (JOGIS)".
Optical Homogeneity (Δn) is guaranteed by use of our He-Ne laser interferometers. The Δn specification is indicated for three diameter ranges (Φ 160 mm or less, Φ 210 mm or less, Φ 260 mm or less) due to the Δn variances caused by glass type, size, and shape. Please note, if the ordered thickness is less than 25 mm, we will use a 25 mm thick test piece for Δn measurement. Please contact us when lower Δn specifications are required.
Refractive Index (ni) Variation within one Lot (Sn Standard)
The indicated Sn value is the refractive index variation after annealing within a single batch (same melt, same annealing run).
Refractive Index Tolerance
The standard refractive index (ni) of our i-line glasses is higher than our catalogue nominal values. This is due to the longer annealing times which are necessary to obtain the desired homogeneity levels. Longer annealing times result in higher refractive indices.
| +20 (+0.00020) means the increase against our catalogue nominal ni value. The ±30 (±0.00030) is then the tolerance on the new nominal value. i.e. a glass type having a tolerance of +20±30 can vary from -10 (-0.00010) to +50 (+0.00050) against standard catalogue nominal. Please consult us when tighter tolerances are required.