FL5 by Hoya

Obsolete Unknown Environmentally Dangerous
Refractive Index vs Wavelength
Refractive Index Calculator
Valid range: 0.25–1.55 µm
dn/dλ vs Wavelength
dn/dλ Calculator
Valid range: 0.25–1.55 µm
Abbe Number Calculator
Transmission vs Wavelength
Transmission Calculator
Valid wavelength range: 0.310–1.550 µm
Optical Properties
Refractive Index (nd) 1.581437
Abbe Number (Vd) 40.887611
Dispersion Formula Schott
Wavelength Range 0.25 — 1.55 µm
$$n(\lambda) = \sqrt{2.44419 - 0.00832456\,\lambda^2 + 0.0190474\,\lambda^{-2} + 0.000504556\,\lambda^{-4} + 3.65765 \times 10^{-6}\,\lambda^{-6} + 1.79355 \times 10^{-6}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 8.9
TCE 100/300°C (10-6/K) 98.0
Thermal Conductivity (W/mK)
Heat Capacity (J/gK)
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[2.09683 \times 10^{-6} + 2(0)\,\Delta T + 3(0)\,\Delta T^2 + \frac{0 + 2(0)\,\Delta T}{\lambda - 0}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 3.24
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
Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd
H-QF50 CDGM 1.58144 40.888972
QF50GTI CDGM 1.58144 40.885954
QF50 CDGM 1.58144 40.885954
LF5HTi Schott 1.58144 40.89
LF5HT Schott 1.581483 40.913786
LF5 Schott 1.58144 40.85
PBL35Y Ohara 1.581591 40.855991
N-LF5 Schott 1.58144 40.848909
B81-41 Corning 1.581396 40.816116
LF5 Sumita 1.58144 40.8
Similar Glasses (Hoya)
Glass Manufacturer nd Vd
E-FL5 Hoya 1.58144 40.89
FL57 Hoya 1.576163 41.39334
FL4 Hoya 1.578447 41.707529
FL7 Hoya 1.57501 41.509668
FL3 Hoya 1.58215 42.028564
FL1 Hoya 1.573091 42.586108
F8 Hoya 1.595514 39.221686
E-F8 Hoya 1.59551 39.22
E-FL6 Hoya 1.56732 42.84
FL6 Hoya 1.567324 42.843119
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