K-VC91 by Sumita

Standard Rare Precision Molding Environmentally Friendly

K-VC91 by Sumita is a standard optical glass with a rare melt frequency. It transmits from 0.34 to 2.00 µm with an nd of 1.8866 and a Vd of 35.0. It has medium thermal expansion (CTE of 7.7×10⁻⁶/K), excellent 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: 0.340–2.000 µm
Optical Properties
Refractive Index (nd) 1.8866
Abbe Number (Vd) 35.0
Dispersion Formula Schott
Wavelength Range 0.36 — 1.55 µm
$$n(\lambda) = \sqrt{3.43993 - 0.0146334\,\lambda^2 + 0.0376252\,\lambda^{-2} + 0.00217488\,\lambda^{-4} - 0.00016418\,\lambda^{-6} + 1.58176 \times 10^{-5}\,\lambda^{-8}}$$
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 Compare
LAH75 Ohara 1.873996 35.258591
S-LAH75 Ohara 1.873996 35.258594
D-ZLAF67 CDGM 1.88385 37.198899
S-LAH92 Ohara 1.891899 37.134024
D-ZLAF67-25 CDGM 1.88259 37.185491
MC-TAFD317 Hoya 1.8812 37.17
M-TAFD307 Hoya 1.88202 37.22
MC-TAFD307 Hoya 1.88202 37.22
MP-TAFD307 Hoya 1.88202 37.22
S-LAH93 Ohara 1.90525 35.036826
Similar Glasses (Sumita)
Glass Manufacturer nd Vd Compare
K-VC91(M) Sumita 1.88175 34.9
K-LaSFn22 Sumita 1.898 34.0
LASFN22 Sumita 1.898 34.0
K-LaSFn23 Sumita 1.911 35.2
K-GIR79 Sumita 1.8592 33.0
LASFN21 Sumita 1.85 32.4
K-LaSFn21 Sumita 1.85 32.4
K-LaSFn17 Sumita 1.883 40.8
LASFN17 Sumita 1.883 40.9
K-VC90 Sumita 1.8528 39.0
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