BALK3 by Sumita

Obsolete Very Rare Environmentally Dangerous
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: 0.290–2.000 µm
Optical Properties
Refractive Index (nd) 1.51835
Abbe Number (Vd) 60.3
Dispersion Formula Schott
Wavelength Range 0.27 — 2.0 µm
$$n(\lambda) = \sqrt{2.27144 - 0.007355\,\lambda^2 + 0.0125283\,\lambda^{-2} - 3.42753 \times 10^{-5}\,\lambda^{-4} + 2.16426 \times 10^{-5}\,\lambda^{-6} - 5.9928 \times 10^{-7}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K)
TCE 100/300°C (10-6/K) 11.0
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) 2.61
Relative Cost
Mechanical Properties
Young's Modulus (GPa)
Poisson's Ratio
Knoop Hardness (kgf/mm²)
Chemical Resistance
Climatic Resistance 2
Stain Resistance
Acid Resistance 1
Alkali Resistance
Phosphate Resistance
Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd
B18-60 Corning 1.518201 60.291781
BALKN3 Schott 1.518489 60.259571
BACL3 Hoya 1.518351 60.396486
UK50 Schott 1.522571 60.383109
K50 Schott 1.522572 60.179756
H-K7 CDGM 1.51478 60.634896
C40 Hoya 1.523 60.4016
S-NSL5 Ohara 1.522494 59.835417
NSL5 Ohara 1.522494 59.790926
K5HT Schott 1.522453 59.530889
Similar Glasses (Sumita)
Glass Manufacturer nd Vd
K5 Sumita 1.52249 59.6
K7 Sumita 1.51112 60.5
KN1 Sumita 1.524 59.3
K3 Sumita 1.51823 59.0
K-PBK60(M) Sumita 1.52483 62.0
K-PBK50(M) Sumita 1.52025 62.2
K-PBK50 Sumita 1.5225 62.3
K-PBK60 Sumita 1.5274 62.3
K11 Sumita 1.50013 61.6
BAK2 Sumita 1.53996 59.7
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