LLF7 by Sumita

Obsolete Very Rare Environmentally Dangerous

LLF7 by Sumita is an obsolete optical glass with a very rare melt frequency. It transmits from 0.31 to 2.00 µm with an nd of 1.54869 and a Vd of 45.4. It has excellent chemical resistance and dangerous environmental properties.

Refractive Index vs Wavelength
Refractive Index Calculator
Valid range: 0.27–2.0 µm
dn/dλ vs Wavelength
dn/dλ Calculator
Valid range: 0.27–2.0 µm
Abbe Number Calculator
Transmission vs Wavelength
Transmission Calculator
Valid wavelength range: 0.310–2.000 µm
Optical Properties
Refractive Index (nd) 1.54869
Abbe Number (Vd) 45.4
Dispersion Formula Schott
Wavelength Range 0.27 — 2.0 µm
$$n(\lambda) = \sqrt{2.35132 - 0.00823454\,\lambda^2 + 0.0161847\,\lambda^{-2} + 0.000338946\,\lambda^{-4} + 7.33135 \times 10^{-6}\,\lambda^{-6} + 8.69223 \times 10^{-7}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) —
TCE 100/300°C (10-6/K) 9.5
Thermal Conductivity (W/mK) —
Heat Capacity (J/gK) —
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[0 + 2(0)\,\Delta T + 3(0)\,\Delta T^2 + \frac{0 + 2(0)\,\Delta T}{\lambda - 0}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 2.97
Relative Cost —
Mechanical Properties
Young's Modulus (GPa) —
Poisson's Ratio —
Knoop Hardness (kgf/mm²) —
Chemical Resistance
Climatic Resistance 1
Stain Resistance —
Acid Resistance 1
Alkali Resistance —
Phosphate Resistance —
Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd Compare
LLF7 Schott 1.548831 45.40834
FEL7 Hoya 1.54883 45.439785
PBL7 Ohara 1.548689 45.555746
B48-46 Corning 1.548098 45.718533
PBL1Y Ohara 1.548141 45.733282
LLF1 Schott 1.54814 45.75
PBL1 Ohara 1.548141 45.781144
S-TIL1 Ohara 1.548141 45.784277
E-FEL1 Hoya 1.54814 45.82
H-QF1 CDGM 1.54814 45.820011
Similar Glasses (Sumita)
Glass Manufacturer nd Vd Compare
LLF1 Sumita 1.54814 45.9
LLF4 Sumita 1.56138 45.3
LLF2 Sumita 1.54072 47.2
LLF8 Sumita 1.53256 46.0
BAF1 Sumita 1.5569 48.5
LF6 Sumita 1.56732 42.8
LLF6 Sumita 1.53172 48.9
LF1 Sumita 1.57309 42.7
BAF3 Sumita 1.58267 46.5
LF7 Sumita 1.57501 41.3
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