BPG2 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: 0.330–2.000 µm
Optical Properties
Refractive Index (nd) 1.5592
Abbe Number (Vd) 53.9
Dispersion Formula Schott
Wavelength Range 0.27 — 2.0 µm
$$n(\lambda) = \sqrt{2.39026 - 0.00873715\,\lambda^2 + 0.0145416\,\lambda^{-2} + 0.000168797\,\lambda^{-4} + 1.30068 \times 10^{-5}\,\lambda^{-6} - 7.18385 \times 10^{-8}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K)
TCE 100/300°C (10-6/K) 7.4
Thermal Conductivity (W/mK)
Heat Capacity (J/gK)
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[0 + 2(0)\,\Delta T + 3(0)\,\Delta T^2 + \frac{0 + 2(0)\,\Delta T}{\lambda - 0}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 2.72
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
K-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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