E-FEL2 by Hoya

Standard Rare Environmentally Friendly

E-FEL2 by Hoya is a standard optical glass with a rare melt frequency. It transmits from 0.34 to 1.55 µm with an nd of 1.54072 and a Vd of 47.2. It has medium thermal expansion (CTE of 8.2×10⁻⁶/K) and excellent chemical resistance.

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: 0.340–1.550 µm
Optical Properties
Refractive Index (nd) 1.54072
Abbe Number (Vd) 47.2
Dispersion Formula Schott
Wavelength Range 0.36501 — 1.5296 µm
$$n(\lambda) = \sqrt{2.3318 - 0.00970422\,\lambda^2 + 0.0140328\,\lambda^{-2} + 0.000648229\,\lambda^{-4} - 4.08138 \times 10^{-5}\,\lambda^{-6} + 3.90649 \times 10^{-6}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 8.2
TCE 100/300°C (10-6/K) 10.0
Thermal Conductivity (W/mK) —
Heat Capacity (J/gK) —
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[0 + 2(0)\,\Delta T + 3(0)\,\Delta T^2 + \frac{0 + 2(0)\,\Delta T}{\lambda - 0}\right] \Delta T = T - T_0, \quad T_0 = 23\,°\text{C}$$
Physical Properties
Density (g/cm³) 2.53
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

General glass Type

Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd Compare
LLF2 Sumita 1.54072 47.2
QF8 CDGM 1.540718 47.198243
S-TIL2 Ohara 1.54072 47.227127
LLF2 Schott 1.540719 47.171344
H-QF8 CDGM 1.54072 47.230007
PBL2 Ohara 1.54072 47.23368
QF70GFI CDGM 1.547 48.161896
LLF8 Sumita 1.53256 46.0
LLF1 Sumita 1.54814 45.9
LLF1HTi Schott 1.54815 45.9
Similar Glasses (Hoya)
Glass Manufacturer nd Vd Compare
FEL2 Hoya 1.540718 47.198247
FF2 Hoya 1.532561 45.942878
FEL1 Hoya 1.548136 45.822169
E-FEL1 Hoya 1.54814 45.82
FEL6 Hoya 1.53172 48.837531
E-FEL6 Hoya 1.53172 48.84
FEL7 Hoya 1.54883 45.439785
FEL3 Hoya 1.560125 47.090971
SBF1 Hoya 1.551151 49.517289
FEL4 Hoya 1.561379 45.226718
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