QF8 by CDGM

Obsolete Rare Environmentally Dangerous

QF8 by CDGM is an obsolete optical glass with a rare melt frequency. It transmits from 0.31 to 2.40 µm with an nd of 1.540718 and a Vd of 47.198243. It has medium thermal expansion (CTE of 8.5×10⁻⁶/K), moderate relative cost, and dangerous environmental properties.

Refractive Index vs Wavelength
Refractive Index Calculator
Valid range: 0.365–0.7065 µm
dn/dλ vs Wavelength
dn/dλ Calculator
Valid range: 0.365–0.7065 µm
Abbe Number Calculator
Transmission vs Wavelength
Transmission Calculator
Valid wavelength range: 0.310–2.400 µm
Optical Properties
Refractive Index (nd) 1.540718
Abbe Number (Vd) 47.198243
Dispersion Formula Schott
Wavelength Range 0.365 — 0.7065 µm
$$n(\lambda) = \sqrt{2.32874 - 0.00786798\,\lambda^2 + 0.0157639\,\lambda^{-2} + 0.000197942\,\lambda^{-4} + 1.80029 \times 10^{-5}\,\lambda^{-6} + 3.65335 \times 10^{-7}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 8.5
TCE 100/300°C (10-6/K) 9.8
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) 2.86
Relative Cost 5.6
Mechanical Properties
Young's Modulus (GPa) 61.75
Poisson's Ratio 0.21
Knoop Hardness (kgf/mm²) 397.0
Chemical Resistance
Climatic Resistance —
Stain Resistance —
Acid Resistance —
Alkali Resistance —
Phosphate Resistance —
Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd Compare
FEL2 Hoya 1.540718 47.198247
LLF2 Sumita 1.54072 47.2
E-FEL2 Hoya 1.54072 47.2
LLF2 Schott 1.540719 47.171344
S-TIL2 Ohara 1.54072 47.227127
PBL2 Ohara 1.54072 47.23368
LLF8 Sumita 1.53256 46.0
LLF1 Sumita 1.54814 45.9
LLF1HTi Schott 1.54815 45.9
LLF1HT Schott 1.548144 45.888593
Similar Glasses (CDGM)
Glass Manufacturer nd Vd Compare
H-QF8 CDGM 1.54072 47.230007
QF70GFI CDGM 1.547 48.161896
QF1 CDGM 1.5481 45.886233
H-QF1 CDGM 1.54814 45.820011
QF6 CDGM 1.531719 48.755584
H-QF6A CDGM 1.53172 48.839833
BAF2 CDGM 1.569703 49.435926
H-BAF2 CDGM 1.5697 49.452646
H-QF56 CDGM 1.56732 42.810117
H-BAF4 CDGM 1.58267 46.597786
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