K-PBK40(M) by Sumita

Preferred Very Common Environmentally Friendly

K-PBK40(M) by Sumita is a preferred optical glass with a very common melt frequency. It transmits from 0.27 to 2.00 µm with an nd of 1.51497 and a Vd of 63.3. It has low thermal expansion (CTE of 5.4×10⁻⁶/K) and good chemical resistance.

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: 0.270–2.000 µm
Optical Properties
Refractive Index (nd) 1.51497
Abbe Number (Vd) 63.3
Dispersion Formula Schott
Wavelength Range 0.36 — 1.55 µm
$$n(\lambda) = \sqrt{2.26667 - 0.0106972\,\lambda^2 + 0.010455\,\lambda^{-2} + 0.000247319\,\lambda^{-4} - 9.42162 \times 10^{-6}\,\lambda^{-6} + 3.33601 \times 10^{-7}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 5.4
TCE 100/300°C (10-6/K) 7.3
Thermal Conductivity (W/mK) —
Heat Capacity (J/gK) —
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[4.91 \times 10^{-6} + 2(2.06 \times 10^{-8})\,\Delta T + 3(1.52 \times 10^{-11})\,\Delta T^2 + \frac{4.18 \times 10^{-7} + 2(1.61 \times 10^{-10})\,\Delta T}{\lambda - 0.165}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 2.39
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
D-K59-25 CDGM 1.51698 63.4085
D-K59 CDGM 1.5176 63.499991
S-BSL7R Ohara 1.51633 63.881689
H-K90GTI CDGM 1.51948 63.291634
H-K5 CDGM 1.510072 63.364525
BSC1 Hoya 1.510091 63.435118
BK1 Schott 1.510091 63.464788
D-K9-25 CDGM 1.51577 63.989637
D-K9GT-25 CDGM 1.51577 63.989637
BK7G18 Schott 1.51975 63.58
Similar Glasses (Sumita)
Glass Manufacturer nd Vd Compare
P-BK40 Sumita 1.5176 63.5
K-PBK40 Sumita 1.5176 63.5
BK1 Sumita 1.51009 63.4
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
K-PBK60(M) Sumita 1.52483 62.0
K-PBK60 Sumita 1.5274 62.3
K11 Sumita 1.50013 61.6
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