N-SSK20 by Schott

Preferred Unknown Environmentally Friendly

N-SSK20 by Schott is a preferred optical glass. It transmits from 0.27 to 2.50 µm with an nd of 1.62568 and a Vd of 50.2. It has medium thermal expansion (CTE of 6.74×10⁻⁶/K) and excellent chemical resistance.

Refractive Index vs Wavelength
Refractive Index Calculator
Valid range: 0.26–2.5 µm
dn/dλ vs Wavelength
dn/dλ Calculator
Valid range: 0.26–2.5 µm
Abbe Number Calculator
Transmission vs Wavelength
Transmission Calculator
Valid wavelength range: 0.270–2.500 µm
Optical Properties
Refractive Index (nd) 1.62568
Abbe Number (Vd) 50.2
Dispersion Formula Sellmeier
Wavelength Range 0.26 — 2.5 µm
$$n(\lambda) = \sqrt{1 + \frac{1.18392\,\lambda^2}{\lambda^2 - 0.00687637} + \frac{0.406467\,\lambda^2}{\lambda^2 - 0.0246713} + \frac{1.10391\,\lambda^2}{\lambda^2 - 132.063}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 6.74
TCE 100/300°C (10-6/K) 8.01
Thermal Conductivity (W/mK) 0.83
Heat Capacity (J/gK) 0.63
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[7.76 \times 10^{-6} + 2(1.26 \times 10^{-8})\,\Delta T + 3(-3.08 \times 10^{-12})\,\Delta T^2 + \frac{8.59 \times 10^{-7} + 2(9.53 \times 10^{-10})\,\Delta T}{\lambda - 0.151}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 3.4501
Relative Cost —
Mechanical Properties
Young's Modulus (GPa) 86.66
Poisson's Ratio 0.27
Knoop Hardness (kgf/mm²) 582.0
Chemical Resistance
Climatic Resistance 1
Stain Resistance 0
Acid Resistance 1
Alkali Resistance 1
Phosphate Resistance 1
Notes

only available as optical components

Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd Compare
BACED9 Hoya 1.620119 49.823001
K-SSK9 Sumita 1.62012 49.8
SSK9 Sumita 1.62012 49.8
BSM28 Ohara 1.617722 49.83232
S-BSM28 Ohara 1.617722 49.815052
K-SSK3 Sumita 1.61484 51.1
SSK3 Sumita 1.61484 51.1
BACED3 Hoya 1.614838 51.1513
BSM23 Ohara 1.614839 51.172377
BAF5 Hoya 1.607292 49.336899
Similar Glasses (Schott)
Glass Manufacturer nd Vd Compare
N-SSK8 Schott 1.61773 49.83
SSKN8 Schott 1.61772 49.771451
SSK3 Schott 1.614837 51.1603
SSK50 Schott 1.617954 52.609086
SSK2 Schott 1.622301 53.154887
N-SSK2 Schott 1.62229 53.27
BAF8 Schott 1.62374 47.000909
BAF9 Schott 1.643276 47.958224
SSK1 Schott 1.617201 53.912403
N-BAF52 Schott 1.60863 46.6
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