SFL4 by Schott

Obsolete Unknown Environmentally Dangerous

SFL4 by Schott is an obsolete optical glass. It transmits from 0.36 to 0.70 µm with an nd of 1.7552 and a Vd of 27.206054. It has medium thermal expansion (CTE of 9.2×10⁻⁶/K), excellent chemical resistance, high relative cost, and dangerous environmental properties.

Refractive Index vs Wavelength
Refractive Index Calculator
Valid range: 0.334–1.06 µm
dn/dλ vs Wavelength
dn/dλ Calculator
Valid range: 0.334–1.06 µm
Abbe Number Calculator
Transmission vs Wavelength
Transmission Calculator
Valid wavelength range: 0.365–0.700 µm
Optical Properties
Refractive Index (nd) 1.7552
Abbe Number (Vd) 27.206054
Dispersion Formula Sellmeier
Wavelength Range 0.334 — 1.06 µm
$$n(\lambda) = \sqrt{1 + \frac{1.68435\,\lambda^2}{\lambda^2 - 0.0128694} + \frac{0.275878\,\lambda^2}{\lambda^2 - 0.06098} + \frac{1.80248\,\lambda^2}{\lambda^2 - 159.614}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 9.2
TCE 100/300°C (10-6/K) 10.8
Thermal Conductivity (W/mK) —
Heat Capacity (J/gK) —
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[-4.9 \times 10^{-6} + 2(8.17 \times 10^{-9})\,\Delta T + 3(-1.71 \times 10^{-11})\,\Delta T^2 + \frac{9.93 \times 10^{-7} + 2(1.45 \times 10^{-9})\,\Delta T}{\lambda - 0.281}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 3.37
Relative Cost 8.28
Mechanical Properties
Young's Modulus (GPa) —
Poisson's Ratio —
Knoop Hardness (kgf/mm²) —
Chemical Resistance
Climatic Resistance —
Stain Resistance 0
Acid Resistance 1
Alkali Resistance 1
Phosphate Resistance —
Notes

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Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd Compare
SF4 Sumita 1.7552 27.5
SF4W Sumita 1.7552 27.5
K-SFLD4 Sumita 1.7552 27.5
S-TIH4 Ohara 1.755199 27.512089
PBH4W Ohara 1.755199 27.512146
PBH4 Ohara 1.755199 27.512146
E-FD4L Hoya 1.7552 27.53
E-FD4 Hoya 1.7552 27.53
H-ZF6 CDGM 1.7552 27.530047
FD4 Hoya 1.755199 27.530242
Similar Glasses (Schott)
Glass Manufacturer nd Vd Compare
N-SF4 Schott 1.75513 27.38
SF4 Schott 1.7552 27.58
SF55 Schott 1.7618 26.950177
SF63 Schott 1.7484 27.713565
N-SF14 Schott 1.76182 26.53
SF14 Schott 1.76182 26.53
SF13 Schott 1.740771 27.59998
SF54 Schott 1.7408 28.090813
SF3 Schott 1.74 28.2
SF10 Schott 1.72825 28.41
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