K-LaK7 by Sumita

Standard Rare 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: 0.290–2.000 µm
Optical Properties
Refractive Index (nd) 1.6516
Abbe Number (Vd) 58.3
Dispersion Formula Schott
Wavelength Range 0.36 — 1.55 µm
$$n(\lambda) = \sqrt{2.68357 - 0.0120865\,\lambda^2 + 0.0151935\,\lambda^{-2} + 0.00064848\,\lambda^{-4} - 5.24239 \times 10^{-5}\,\lambda^{-6} + 2.83015 \times 10^{-6}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 6.8
TCE 100/300°C (10-6/K) 8.4
Thermal Conductivity (W/mK)
Heat Capacity (J/gK)
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[-2.13 \times 10^{-6} + 2(1.62 \times 10^{-8})\,\Delta T + 3(-5.04 \times 10^{-11})\,\Delta T^2 + \frac{3.71 \times 10^{-7} + 2(6.15 \times 10^{-10})\,\Delta T}{\lambda - 0.214}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 3.76
Relative Cost
Mechanical Properties
Young's Modulus (GPa)
Poisson's Ratio
Knoop Hardness (kgf/mm²)
Chemical Resistance
Climatic Resistance 2
Stain Resistance
Acid Resistance 5
Alkali Resistance
Phosphate Resistance
Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd
LAC7 Hoya 1.6516 58.4
H-LAK50A CDGM 1.6516 58.403057
C52-58 Corning 1.6516 58.511488
LAKN7 Schott 1.6516 58.517773
LAL7 Ohara 1.651597 58.519433
N-LAK7 Schott 1.6516 58.52
S-LAL7Q Ohara 1.6516 58.544459
S-LAL7 Ohara 1.651597 58.550655
BSM36 Ohara 1.642495 58.369399
S-BSM36 Ohara 1.642495 58.369399
Similar Glasses (Sumita)
Glass Manufacturer nd Vd
LAK7 Sumita 1.6516 58.3
K-LaK6 Sumita 1.6425 58.1
LAK6 Sumita 1.6425 58.1
K-LaK11 Sumita 1.6583 57.3
LAK11 Sumita 1.6583 57.3
LAKN13 Sumita 1.641 56.8
LAKN2 Sumita 1.6405 60.1
K-LaKn2 Sumita 1.6405 60.1
LAKN5 Sumita 1.65 55.8
K-LaKn5 Sumita 1.65 55.8
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