NBFD9 by Hoya

Obsolete Unknown Environmentally Dangerous
Refractive Index vs Wavelength
Refractive Index Calculator
Valid range: 0.334–2.325 µm
dn/dλ vs Wavelength
dn/dλ Calculator
Valid range: 0.334–2.325 µm
Abbe Number Calculator
Transmission vs Wavelength

No transmission data available.

Optical Properties
Refractive Index (nd) 1.756898
Abbe Number (Vd) 31.798532
Dispersion Formula Schott
Wavelength Range 0.334 — 2.325 µm
$$n(\lambda) = \sqrt{2.98288 - 0.0115477\,\lambda^2 + 0.0328352\,\lambda^{-2} + 0.00163548\,\lambda^{-4} - 7.36858 \times 10^{-5}\,\lambda^{-6} + 1.07051 \times 10^{-5}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K)
TCE 100/300°C (10-6/K)
Thermal Conductivity (W/mK)
Heat Capacity (J/gK)
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[0 + 2(0)\,\Delta T + 3(0)\,\Delta T^2 + \frac{0 + 2(0)\,\Delta T}{\lambda - 0}\right] \Delta T = T - T_0, \quad T_0 = 25\,°\text{C}$$
Physical Properties
Density (g/cm³)
Relative Cost
Mechanical Properties
Young's Modulus (GPa)
Poisson's Ratio
Knoop Hardness (kgf/mm²)
Chemical Resistance
Climatic Resistance
Stain Resistance
Acid Resistance
Alkali Resistance
Phosphate Resistance
Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd
LAF11A Schott 1.756927 31.702906
LAFN12 Sumita 1.7569 31.7
BPH50 Ohara 1.739997 31.710001
KZFS50 Sumita 1.74 31.7
S-NBH53 Ohara 1.737999 32.261312
S-NBH53V Ohara 1.737999 32.32659
H-TF29 CDGM 1.77047 29.806014
BASF54 Schott 1.73627 32.149453
N-LAF7 Schott 1.7495 34.82
LAFN7 Schott 1.7495 34.95
Similar Glasses (Hoya)
Glass Manufacturer nd Vd
ADF505 Hoya 1.739996 31.655919
NBFD29 Hoya 1.77047 29.74
E-LAF7 Hoya 1.7495 35.04
LAF7 Hoya 1.749497 35.042695
NBFD32 Hoya 1.73037 32.23
FD41 Hoya 1.750839 27.686615
FD3 Hoya 1.739999 28.245048
FD4 Hoya 1.755199 27.530242
E-FD4 Hoya 1.7552 27.53
E-FD4L Hoya 1.7552 27.53
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