K-VC91(M) 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: 0.340–2.000 µm
Optical Properties
Refractive Index (nd) 1.88175
Abbe Number (Vd) 34.9
Dispersion Formula Schott
Wavelength Range 0.36 — 1.55 µm
$$n(\lambda) = \sqrt{3.42266 - 0.0146206\,\lambda^2 + 0.0377121\,\lambda^{-2} + 0.00190151\,\lambda^{-4} - 0.000110428\,\lambda^{-6} + 1.24775 \times 10^{-5}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 7.7
TCE 100/300°C (10-6/K) 9.5
Thermal Conductivity (W/mK)
Heat Capacity (J/gK)
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[-1.08 \times 10^{-6} + 2(1.12 \times 10^{-8})\,\Delta T + 3(-9.02 \times 10^{-11})\,\Delta T^2 + \frac{8.61 \times 10^{-7} + 2(1.32 \times 10^{-9})\,\Delta T}{\lambda - 0.245}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 4.87
Relative Cost
Mechanical Properties
Young's Modulus (GPa)
Poisson's Ratio
Knoop Hardness (kgf/mm²)
Chemical Resistance
Climatic Resistance 1
Stain Resistance
Acid Resistance 1
Alkali Resistance
Phosphate Resistance
Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd
LAH75 Ohara 1.873996 35.258591
S-LAH75 Ohara 1.873996 35.258594
MC-TAFD317 Hoya 1.8812 37.17
D-ZLAF67-25 CDGM 1.88259 37.185491
D-ZLAF67 CDGM 1.88385 37.198899
M-TAFD307 Hoya 1.88202 37.22
MP-TAFD307 Hoya 1.88202 37.22
MC-TAFD307 Hoya 1.88202 37.22
S-LAH92 Ohara 1.891899 37.134024
S-LAH93 Ohara 1.90525 35.036826
Similar Glasses (Sumita)
Glass Manufacturer nd Vd
K-VC91 Sumita 1.8866 35.0
K-LaSFn22 Sumita 1.898 34.0
LASFN22 Sumita 1.898 34.0
K-GIR79 Sumita 1.8592 33.0
K-LaSFn23 Sumita 1.911 35.2
LASFN21 Sumita 1.85 32.4
K-LaSFn21 Sumita 1.85 32.4
K-VC90 Sumita 1.8528 39.0
K-LaSFn17 Sumita 1.883 40.8
LASFN17 Sumita 1.883 40.9
Compare Glasses