N-SF57HTultra by Schott

Preferred Unknown Environmentally Friendly

N-SF57HTultra by Schott is a preferred optical glass. It transmits from 0.37 to 2.50 µm with an nd of 1.84666 and a Vd of 23.78. It has medium thermal expansion (CTE of 8.46×10⁻⁶/K), excellent chemical resistance, and moderate relative cost.

Refractive Index vs Wavelength
Refractive Index Calculator
Valid range: 0.37–2.5 µm
dn/dλ vs Wavelength
dn/dλ Calculator
Valid range: 0.37–2.5 µm
Abbe Number Calculator
Transmission vs Wavelength
Transmission Calculator
Valid wavelength range: 0.370–2.500 µm
Optical Properties
Refractive Index (nd) 1.84666
Abbe Number (Vd) 23.78
Dispersion Formula Sellmeier
Wavelength Range 0.37 — 2.5 µm
$$n(\lambda) = \sqrt{1 + \frac{1.87544\,\lambda^2}{\lambda^2 - 0.014175} + \frac{0.373757\,\lambda^2}{\lambda^2 - 0.064051} + \frac{2.30002\,\lambda^2}{\lambda^2 - 177.39}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 8.46
TCE 100/300°C (10-6/K) 9.88
Thermal Conductivity (W/mK) 0.99
Heat Capacity (J/gK) 0.66
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[-4.51 \times 10^{-6} + 2(8.73 \times 10^{-9})\,\Delta T + 3(-1.64 \times 10^{-11})\,\Delta T^2 + \frac{1.07 \times 10^{-6} + 2(1.57 \times 10^{-9})\,\Delta T}{\lambda - 0.295}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 3.533
Relative Cost 6.6
Mechanical Properties
Young's Modulus (GPa) 96.0
Poisson's Ratio 0.26
Knoop Hardness (kgf/mm²) 520.0
Chemical Resistance
Climatic Resistance 1
Stain Resistance 0
Acid Resistance 1
Alkali Resistance 1
Phosphate Resistance 1
Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd Compare
FDS90 Hoya 1.84666 23.78
FDS90-SG Hoya 1.84666 23.78
TIH53 Ohara 1.846659 23.780116
S-TIH53 Ohara 1.84666 23.77794
S-TIH53W Ohara 1.84666 23.77794
H-ZF52GT CDGM 1.84666 23.784497
H-ZF52 CDGM 1.84666 23.784497
H-ZF52TT CDGM 1.84666 23.784497
L-TIH53 Ohara 1.84666 23.773536
H-ZF52A CDGM 1.84667 23.791236
Similar Glasses (Schott)
Glass Manufacturer nd Vd Compare
N-SF57 Schott 1.84666 23.78
N-SF57HT Schott 1.84666 23.78
SF57HHT Schott 1.84666 23.779912
SF57HT Schott 1.84666 23.83
SF57HTultra Schott 1.84666 23.83
SF57 Schott 1.84666 23.83
SFL57 Schott 1.84666 23.62
SF6G05 Schott 1.80906 25.27
N-SF6HTultra Schott 1.80518 25.36
N-SF6 Schott 1.80518 25.36
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