K-BPG2 by Sumita

Standard Very Common 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: 0.330–2.000 µm
Optical Properties
Refractive Index (nd) 1.5592
Abbe Number (Vd) 53.9
Dispersion Formula Schott
Wavelength Range 0.36 — 1.55 µm
$$n(\lambda) = \sqrt{2.39093 - 0.00902412\,\lambda^2 + 0.0140366\,\lambda^{-2} + 0.000331084\,\lambda^{-4} - 9.98523 \times 10^{-6}\,\lambda^{-6} + 1.10709 \times 10^{-6}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 6.0
TCE 100/300°C (10-6/K) 7.4
Thermal Conductivity (W/mK)
Heat Capacity (J/gK)
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[6.45 \times 10^{-6} + 2(1.89 \times 10^{-8})\,\Delta T + 3(-2.11 \times 10^{-10})\,\Delta T^2 + \frac{5.53 \times 10^{-7} + 2(8.99 \times 10^{-10})\,\Delta T}{\lambda - 0.207}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 2.72
Relative Cost
Mechanical Properties
Young's Modulus (GPa)
Poisson's Ratio
Knoop Hardness (kgf/mm²)
Chemical Resistance
Climatic Resistance 1
Stain Resistance
Acid Resistance 1
Alkali Resistance
Phosphate Resistance
Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd
N-KZFS2 Schott 1.55836 54.01
KZFSN2 Schott 1.558361 54.157173
ADF1 Hoya 1.564997 52.958253
B58-53 Corning 1.557511 52.533062
B48-53 Corning 1.547753 53.492251
BALF5 Schott 1.547391 53.629486
N-BALF5 Schott 1.54739 53.63
BAL5 Ohara 1.547393 53.550738
BAFL3 Hoya 1.571348 52.982526
BAL3 Ohara 1.571351 52.968158
Similar Glasses (Sumita)
Glass Manufacturer nd Vd
BPG2 Sumita 1.5592 53.9
BALF5 Sumita 1.54739 53.6
BALF3 Sumita 1.57135 53.0
BAK4 Sumita 1.56883 56.0
BAK1 Sumita 1.5725 57.5
BALF6 Sumita 1.58904 53.2
K-CSK158(M) Sumita 1.58157 56.7
KF4 Sumita 1.53358 51.6
K-CSK158 Sumita 1.584 56.9
KZF2 Sumita 1.52944 51.8
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