FDS18-W by Hoya

Preferred Very Common Environmentally Dangerous

FDS18-W by Hoya is a preferred optical glass with a very common melt frequency. It transmits from 0.39 to 1.55 µm with an nd of 1.94595 and a Vd of 17.98. It has low thermal expansion (CTE of 5.4×10⁻⁶/K), excellent chemical resistance, and dangerous environmental properties.

Refractive Index vs Wavelength
Refractive Index Calculator
Valid range: 0.36501–1.5296 µm
dn/dλ vs Wavelength
dn/dλ Calculator
Valid range: 0.36501–1.5296 µm
Abbe Number Calculator
Transmission vs Wavelength
Transmission Calculator
Valid wavelength range: 0.390–1.550 µm
Optical Properties
Refractive Index (nd) 1.94595
Abbe Number (Vd) 17.98
Dispersion Formula Schott
Wavelength Range 0.36501 — 1.5296 µm
$$n(\lambda) = \sqrt{3.56378 - 0.0254496\,\lambda^2 + 0.0584017\,\lambda^{-2} + 0.0092311\,\lambda^{-4} - 0.000954997\,\lambda^{-6} + 0.000117775\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 5.4
TCE 100/300°C (10-6/K) 7.1
Thermal Conductivity (W/mK) —
Heat Capacity (J/gK) —
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[-1.61 \times 10^{-6} + 2(1.15 \times 10^{-8})\,\Delta T + 3(-4.58 \times 10^{-11})\,\Delta T^2 + \frac{1.17 \times 10^{-6} + 2(1.89 \times 10^{-9})\,\Delta T}{\lambda - 0.324}\right] \Delta T = T - T_0, \quad T_0 = 23\,°\text{C}$$
Physical Properties
Density (g/cm³) 3.51
Relative Cost —
Mechanical Properties
Young's Modulus (GPa) —
Poisson's Ratio —
Knoop Hardness (kgf/mm²) —
Chemical Resistance
Climatic Resistance 1
Stain Resistance 1
Acid Resistance 1
Alkali Resistance —
Phosphate Resistance —
Notes

Recommended glass type

Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd Compare
H-ZF88GT CDGM 1.94595 17.941964
H-ZF88 CDGM 1.94595 17.941964
H-ZF73 CDGM 1.95906 17.472434
H-ZF73GT CDGM 1.95906 17.472434
S-NPH3 Ohara 1.95906 17.471252
SF59 Schott 1.952497 20.363706
H-ZF72A CDGM 1.92286 18.895887
H-ZF72AGT CDGM 1.92286 18.895887
S-NPH2 Ohara 1.92286 18.896912
H-ZF62 CDGM 1.92286 20.879915
Similar Glasses (Hoya)
Glass Manufacturer nd Vd Compare
FDS18 Hoya 1.94595 17.98
MP-FDS1 Hoya 1.92286 20.88
M-FDS1 Hoya 1.92286 20.88
E-FDS1-W Hoya 1.92286 20.88
E-FDS1 Hoya 1.92286 20.88
FDS1 Hoya 1.922859 20.883457
FDS165-W Hoya 1.98611 17.25
FDS16-W Hoya 1.98612 16.48
FDS24-W Hoya 1.92119 23.96
FDS24-SW Hoya 1.92119 23.96
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