E-FD4 by Hoya

Special Very Rare Environmentally Friendly
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: 0.370–1.550 µm
Optical Properties
Refractive Index (nd) 1.7552
Abbe Number (Vd) 27.53
Dispersion Formula Schott
Wavelength Range 0.36501 — 1.5296 µm
$$n(\lambda) = \sqrt{2.96732 - 0.0139896\,\lambda^2 + 0.0334567\,\lambda^{-2} + 0.00307178\,\lambda^{-4} - 0.000266824\,\lambda^{-6} + 2.89502 \times 10^{-5}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 8.7
TCE 100/300°C (10-6/K) 10.0
Thermal Conductivity (W/mK)
Heat Capacity (J/gK)
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[1.675 \times 10^{-7} + 2(0)\,\Delta T + 3(0)\,\Delta T^2 + \frac{0 + 2(0)\,\Delta T}{\lambda - 0}\right] \Delta T = T - T_0, \quad T_0 = 23\,°\text{C}$$
Physical Properties
Density (g/cm³) 3.23
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

Not in a position to accept new order because of discontinuation.

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Glass Manufacturer nd Vd
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Similar Glasses (Hoya)
Glass Manufacturer nd Vd
E-FD4L Hoya 1.7552 27.53
FD4 Hoya 1.755199 27.530242
FD41 Hoya 1.750839 27.686615
FDS5 Hoya 1.761804 26.914901
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FD14 Hoya 1.761823 26.552048
E-FD13 Hoya 1.74077 27.76
FD13 Hoya 1.740774 27.764991
FD3 Hoya 1.739999 28.245048
FF8 Hoya 1.75211 25.05
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