BK1 by Sumita

Obsolete Very Rare Environmentally Dangerous

BK1 by Sumita is an obsolete optical glass with a very rare melt frequency. It transmits from 0.29 to 2.00 µm with an nd of 1.51009 and a Vd of 63.4. It has good chemical resistance and dangerous environmental properties.

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) 1.51009
Abbe Number (Vd) 63.4
Dispersion Formula Schott
Wavelength Range 0.27 — 2.0 µm
$$n(\lambda) = \sqrt{2.25087 - 0.00907651\,\lambda^2 + 0.0108456\,\lambda^{-2} + 0.000141189\,\lambda^{-4} + 1.33186 \times 10^{-6}\,\lambda^{-6} + 5.96885 \times 10^{-8}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) —
TCE 100/300°C (10-6/K) 9.1
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) 2.47
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 Compare
BSC1 Hoya 1.510091 63.435118
H-K5 CDGM 1.510072 63.364525
BK1 Schott 1.510091 63.464788
B10-63 Corning 1.509992 63.551713
BSL1 Ohara 1.510091 63.635037
AF32ECO Schott 1.511531 62.574031
D-K59-25 CDGM 1.51698 63.4085
D-K9-25 CDGM 1.51577 63.989637
D-K9GT-25 CDGM 1.51577 63.989637
S-BSL7R Ohara 1.51633 63.881689
Similar Glasses (Sumita)
Glass Manufacturer nd Vd Compare
K-PBK40(M) Sumita 1.51497 63.3
K-PBK40 Sumita 1.5176 63.5
P-BK40 Sumita 1.5176 63.5
K-BK7 Sumita 1.51633 64.1
BK7 Sumita 1.51633 64.1
K-PBK50(M) Sumita 1.52025 62.2
K-PBK50 Sumita 1.5225 62.3
K11 Sumita 1.50013 61.6
BK3 Sumita 1.49831 65.1
K-PBK60(M) Sumita 1.52483 62.0
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