FTM8 by Ohara

Obsolete Unknown Environmentally Dangerous
Refractive Index vs Wavelength
Refractive Index Calculator
Valid range: 0.3–2.4 µm
dn/dλ vs Wavelength
dn/dλ Calculator
Valid range: 0.3–2.4 µm
Abbe Number Calculator
Transmission vs Wavelength
Transmission Calculator
Valid wavelength range: 0.360–0.700 µm
Optical Properties
Refractive Index (nd) 1.532565
Abbe Number (Vd) 45.914102
Dispersion Formula Schott
Wavelength Range 0.3 — 2.4 µm
$$n(\lambda) = \sqrt{2.30634 - 0.00929943\,\lambda^2 + 0.0141485\,\lambda^{-2} + 0.000619449\,\lambda^{-4} - 3.54213 \times 10^{-5}\,\lambda^{-6} + 4.3561 \times 10^{-6}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 8.5
TCE 100/300°C (10-6/K) 9.7
Thermal Conductivity (W/mK)
Heat Capacity (J/gK)
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[-2.683 \times 10^{-6} + 2(0)\,\Delta T + 3(0)\,\Delta T^2 + \frac{0 + 2(0)\,\Delta T}{\lambda - 0}\right] \Delta T = T - T_0, \quad T_0 = 25\,°\text{C}$$
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
Stain Resistance
Acid Resistance 1
Alkali Resistance
Phosphate Resistance 1
Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd
FF2 Hoya 1.532561 45.942878
LLF8 Sumita 1.53256 46.0
LLF2 Schott 1.540719 47.171344
QF8 CDGM 1.540718 47.198243
FEL2 Hoya 1.540718 47.198247
E-FEL2 Hoya 1.54072 47.2
LLF2 Sumita 1.54072 47.2
H-QF8 CDGM 1.54072 47.230007
QF1 CDGM 1.5481 45.886233
LLF1 Sumita 1.54814 45.9
Similar Glasses (Ohara)
Glass Manufacturer nd Vd
S-TIL2 Ohara 1.54072 47.227127
PBL2 Ohara 1.54072 47.23368
S-TIL1 Ohara 1.548141 45.784277
PBL1 Ohara 1.548141 45.781144
PBL1Y Ohara 1.548141 45.733282
PBL7 Ohara 1.548689 45.555746
S-TIL6 Ohara 1.531717 48.840718
PBL6 Ohara 1.531717 48.904553
PBL6Y Ohara 1.531717 48.956017
PBL26Y Ohara 1.567322 42.855569
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