K-GIR140 by Sumita

Standard Rare Environmentally Friendly

K-GIR140 by Sumita is a standard optical glass with a rare melt frequency. It transmits from 0.28 to 2.00 µm with an nd of 1.75106 and a Vd of 43.1. It has low thermal expansion (CTE of 5.9×10⁻⁶/K) and average chemical resistance.

Refractive Index vs Wavelength
Refractive Index Calculator
Valid range: 0.36–2.3 µm
dn/dλ vs Wavelength
dn/dλ Calculator
Valid range: 0.36–2.3 µm
Abbe Number Calculator
Transmission vs Wavelength
Transmission Calculator
Valid wavelength range: 0.280–2.000 µm
Optical Properties
Refractive Index (nd) 1.75106
Abbe Number (Vd) 43.1
Dispersion Formula Schott
Wavelength Range 0.36 — 2.3 µm
$$n(\lambda) = \sqrt{2.98546 - 0.0065859\,\lambda^2 + 0.0264079\,\lambda^{-2} + 0.000846954\,\lambda^{-4} - 3.25056 \times 10^{-5}\,\lambda^{-6} + 3.18785 \times 10^{-6}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 5.9
TCE 100/300°C (10-6/K) 9.7
Thermal Conductivity (W/mK) —
Heat Capacity (J/gK) —
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[5.13 \times 10^{-6} + 2(1.39 \times 10^{-8})\,\Delta T + 3(-3.39 \times 10^{-10})\,\Delta T^2 + \frac{9.92 \times 10^{-7} + 2(9.74 \times 10^{-10})\,\Delta T}{\lambda - 0.216}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 5.24
Relative Cost —
Mechanical Properties
Young's Modulus (GPa) —
Poisson's Ratio —
Knoop Hardness (kgf/mm²) —
Chemical Resistance
Climatic Resistance 1
Stain Resistance —
Acid Resistance 4
Alkali Resistance —
Phosphate Resistance —
Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd Compare
LAF2 Schott 1.744002 44.719972
S-LAM2 Ohara 1.743997 44.786431
LAM2 Ohara 1.743997 44.787528
D44-45 Corning 1.744001 44.818533
N-LAF2 Schott 1.74397 44.85
LAF20 Hoya 1.744 44.872914
LAF2 Hoya 1.744 44.9
H-LAF3B CDGM 1.744 44.900027
LAFN8 Schott 1.735197 41.590899
P-LAF37 Schott 1.7555 45.66
Similar Glasses (Sumita)
Glass Manufacturer nd Vd Compare
K-LaF2 Sumita 1.744 44.9
LAF2 Sumita 1.744 44.9
K-VC174(M) Sumita 1.74578 45.1
K-VC174 Sumita 1.7485 45.3
K-VC82(M) Sumita 1.75028 45.4
VC81 Sumita 1.75512 45.6
K-VC82 Sumita 1.7555 45.6
LAFN9 Sumita 1.764 40.3
LAFN4 Sumita 1.72 43.7
LAFN10 Sumita 1.72016 42.1
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