K-SSK4 by Sumita

Standard Rare Environmentally Friendly
Refractive Index vs Wavelength
Refractive Index Calculator
Valid range: 0.36–1.55 µm
dn/dλ vs Wavelength
dn/dλ Calculator
Valid range: 0.36–1.55 µm
Abbe Number Calculator
Transmission vs Wavelength
Transmission Calculator
Valid wavelength range: 0.270–2.000 µm
Optical Properties
Refractive Index (nd) 1.61765
Abbe Number (Vd) 55.1
Dispersion Formula Schott
Wavelength Range 0.36 — 1.55 µm
$$n(\lambda) = \sqrt{2.57207 - 0.0105642\,\lambda^2 + 0.0156256\,\lambda^{-2} + 0.000405932\,\lambda^{-4} - 1.34241 \times 10^{-5}\,\lambda^{-6} + 6.43556 \times 10^{-7}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 7.1
TCE 100/300°C (10-6/K) 8.4
Thermal Conductivity (W/mK)
Heat Capacity (J/gK)
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[1.84 \times 10^{-6} + 2(1.42 \times 10^{-8})\,\Delta T + 3(-1.94 \times 10^{-10})\,\Delta T^2 + \frac{5.13 \times 10^{-7} + 2(7.12 \times 10^{-10})\,\Delta T}{\lambda - 0.198}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 3.39
Relative Cost
Mechanical Properties
Young's Modulus (GPa)
Poisson's Ratio
Knoop Hardness (kgf/mm²)
Chemical Resistance
Climatic Resistance 2
Stain Resistance
Acid Resistance 4
Alkali Resistance
Phosphate Resistance
Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd
C17-55 Corning 1.617605 55.123455
SSK4A Schott 1.61765 55.141867
BSM24 Ohara 1.617646 55.049782
BACED4 Hoya 1.617652 55.15751
H-ZK8 CDGM 1.61405 55.116283
BACD9 Hoya 1.614047 55.118097
S-BSM9 Ohara 1.614047 54.990097
BSM9 Ohara 1.614047 54.971106
S-BSM21 Ohara 1.617195 54.062144
BSM21 Ohara 1.617196 54.040511
Similar Glasses (Sumita)
Glass Manufacturer nd Vd
SSK4 Sumita 1.61765 55.1
SK9 Sumita 1.61405 55.1
K-SSK1 Sumita 1.6172 54.0
SSK1 Sumita 1.6172 54.0
SK1 Sumita 1.61025 56.5
SK10 Sumita 1.6228 56.9
SSK2 Sumita 1.6223 53.1
SK2 Sumita 1.60738 56.7
K-VC79(M) Sumita 1.60737 57.2
K-SK18RH Sumita 1.63854 55.5
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