N-FK58 by Schott

Preferred Unknown Environmentally Friendly

N-FK58 by Schott is a preferred optical glass. It transmits from 0.26 to 2.50 µm with an nd of 1.456 and a Vd of 90.9. It has high thermal expansion (CTE of 13.67×10⁻⁶/K), below average chemical resistance, and high relative cost.

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: 0.260–2.500 µm
Optical Properties
Refractive Index (nd) 1.456
Abbe Number (Vd) 90.9
Dispersion Formula Sellmeier
Wavelength Range 0.26 — 2.5 µm
$$n(\lambda) = \sqrt{1 + \frac{0.738043\,\lambda^2}{\lambda^2 - 0.00339066} + \frac{0.363372\,\lambda^2}{\lambda^2 - 0.0117551} + \frac{0.989296\,\lambda^2}{\lambda^2 - 212.842}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 13.67
TCE 100/300°C (10-6/K) 15.72
Thermal Conductivity (W/mK) 0.76
Heat Capacity (J/gK) 0.71
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[-2.05 \times 10^{-5} + 2(-6.33 \times 10^{-9})\,\Delta T + 3(4.13 \times 10^{-11})\,\Delta T^2 + \frac{3.84 \times 10^{-7} + 2(1.63 \times 10^{-10})\,\Delta T}{\lambda - 0.073}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 3.646
Relative Cost 8.6
Mechanical Properties
Young's Modulus (GPa) 70.0
Poisson's Ratio 0.3
Knoop Hardness (kgf/mm²) 372.0
Chemical Resistance
Climatic Resistance 1
Stain Resistance 1
Acid Resistance 52
Alkali Resistance 3
Phosphate Resistance 4
Notes

XLD glass

Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd Compare
H-FK71A CDGM 1.456498 90.470884
FPL52 Ohara 1.455999 90.31888
S-FPL52 Ohara 1.455999 90.288026
H-FK71 CDGM 1.4565 90.273821
FCD10 Hoya 1.4565 90.27
FCD10A Hoya 1.4586 90.19
K-PFK90 Sumita 1.4588 90.0
K-PFK90(M) Sumita 1.45733 89.8
SRF2 Generic IR 1.437925 91.593259
LIYF4 Generic Birefringent 1.453776 93.549426
Similar Glasses (Schott)
Glass Manufacturer nd Vd Compare
FK54 Schott 1.437 90.702365
N-FK56 Schott 1.43425 94.953489
LITHOTEC-CAF2 Schott 1.43385 95.23
ULTRAN20 Schott 1.486561 84.473976
N-FK51A Schott 1.48656 84.47
N-FK51 Schott 1.48656 84.47
FK51 Schott 1.486561 84.467994
FK52 Schott 1.486052 81.802215
N-PK52 Schott 1.497005 81.633263
N-PK52A Schott 1.497 81.61
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