K-SK4 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: 0.280–2.000 µm
Optical Properties
Refractive Index (nd) 1.61272
Abbe Number (Vd) 58.6
Dispersion Formula Schott
Wavelength Range 0.36 — 1.55 µm
$$n(\lambda) = \sqrt{2.55877 - 0.00980956\,\lambda^2 + 0.0148406\,\lambda^{-2} + 0.000319317\,\lambda^{-4} - 1.01644 \times 10^{-5}\,\lambda^{-6} + 6.65188 \times 10^{-7}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 6.1
TCE 100/300°C (10-6/K) 7.6
Thermal Conductivity (W/mK)
Heat Capacity (J/gK)
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[4.04 \times 10^{-7} + 2(1.86 \times 10^{-8})\,\Delta T + 3(-3.68 \times 10^{-10})\,\Delta T^2 + \frac{4.13 \times 10^{-7} + 2(4.69 \times 10^{-10})\,\Delta T}{\lambda - 0.197}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 3.58
Relative Cost
Mechanical Properties
Young's Modulus (GPa)
Poisson's Ratio
Knoop Hardness (kgf/mm²)
Chemical Resistance
Climatic Resistance 3
Stain Resistance
Acid Resistance 4
Alkali Resistance
Phosphate Resistance
Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd
BACD4 Hoya 1.61272 58.58
H-ZK6 CDGM 1.61272 58.577083
SK4 Schott 1.61272 58.629829
C13-58 Corning 1.612693 58.570371
N-SK4 Schott 1.61272 58.63
S-BSM4 Ohara 1.612716 58.716945
BSM4 Ohara 1.612716 58.749129
H-ZK4 CDGM 1.60881 58.855991
BACD3 Hoya 1.608812 58.863994
SK3 Schott 1.60881 58.921505
Similar Glasses (Sumita)
Glass Manufacturer nd Vd
SK4 Sumita 1.61272 58.6
K-PSK200(M) Sumita 1.61083 58.9
K-PSK200 Sumita 1.61305 59.0
SK3 Sumita 1.60881 58.9
K-VC79 Sumita 1.61035 57.9
VC79 Sumita 1.6097 57.8
SK7 Sumita 1.60729 59.5
K-SK7 Sumita 1.60729 59.5
K-SK15 Sumita 1.62299 58.1
SK15 Sumita 1.62299 58.1
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