K-LaFK65 by Sumita

Standard Rare Precision Molding Environmentally Friendly

K-LaFK65 by Sumita is a standard optical glass with a rare melt frequency. It transmits from 0.27 to 2.00 µm with an nd of 1.6567 and a Vd of 62.3. It has medium thermal expansion (CTE of 8.1×10⁻⁶/K), average chemical resistance, and precision molding compatibility.

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) 1.6567
Abbe Number (Vd) 62.3
Dispersion Formula Schott
Wavelength Range 0.36 — 1.55 µm
$$n(\lambda) = \sqrt{2.70166 - 0.0116178\,\lambda^2 + 0.0155977\,\lambda^{-2} + 0.000191112\,\lambda^{-4} + 1.13232 \times 10^{-5}\,\lambda^{-6} - 5.96309 \times 10^{-7}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 8.1
TCE 100/300°C (10-6/K) 10.3
Thermal Conductivity (W/mK) —
Heat Capacity (J/gK) —
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[-7.58 \times 10^{-6} + 2(9.42 \times 10^{-9})\,\Delta T + 3(-3.47 \times 10^{-11})\,\Delta T^2 + \frac{3.97 \times 10^{-7} + 2(4.24 \times 10^{-10})\,\Delta T}{\lambda - 0.182}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 4.36
Relative Cost —
Mechanical Properties
Young's Modulus (GPa) —
Poisson's Ratio —
Knoop Hardness (kgf/mm²) —
Chemical Resistance
Climatic Resistance 1
Stain Resistance —
Acid Resistance 5
Alkali Resistance —
Phosphate Resistance —
Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd Compare
H-LAK4L CDGM 1.64 60.202769
C41-60 Corning 1.640495 60.130957
LACL60 Hoya 1.64 60.2
LAK21 Schott 1.640495 60.101885
N-LAK21 Schott 1.64049 60.1
LACL6 Hoya 1.640003 60.153568
BSM81 Ohara 1.639999 60.091709
S-BSM81 Ohara 1.639999 60.078127
LAKL21 Schott 1.64048 59.749915
S-LAL7 Ohara 1.651597 58.550655
Similar Glasses (Sumita)
Glass Manufacturer nd Vd Compare
K-LaFK65(M) Sumita 1.65224 62.2
K-LaFK63 Sumita 1.6386 63.4
K-LaFK63(M) Sumita 1.63463 63.0
K-LaKn2 Sumita 1.6405 60.1
LAKN2 Sumita 1.6405 60.1
LAFK60 Sumita 1.63246 63.8
K-LaFK60 Sumita 1.63246 63.8
K-LaFK60(M) Sumita 1.62848 63.2
K-LaK7 Sumita 1.6516 58.3
LAK7 Sumita 1.6516 58.3
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