NBFD27 by Hoya

Preferred Very Common Environmentally Dangerous

NBFD27 by Hoya is a preferred optical glass with a very common melt frequency. It transmits from 0.36 to 2.50 µm with an nd of 1.9011 and a Vd of 27.06. It has medium thermal expansion (CTE of 7.1×10⁻⁶/K), excellent chemical resistance, and dangerous environmental properties.

Refractive Index vs Wavelength
Refractive Index Calculator
Valid range: 0.36501–1.5296 µm
dn/dλ vs Wavelength
dn/dλ Calculator
Valid range: 0.36501–1.5296 µm
Abbe Number Calculator
Transmission vs Wavelength
Transmission Calculator
Valid wavelength range: 0.360–2.500 µm
Optical Properties
Refractive Index (nd) 1.9011
Abbe Number (Vd) 27.06
Dispersion Formula Schott
Wavelength Range 0.36501 — 1.5296 µm
$$n(\lambda) = \sqrt{3.46133 - 0.0158781\,\lambda^2 + 0.0461568\,\lambda^{-2} + 0.00339272\,\lambda^{-4} - 0.000247499\,\lambda^{-6} + 3.1074 \times 10^{-5}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 7.1
TCE 100/300°C (10-6/K) 8.6
Thermal Conductivity (W/mK) —
Heat Capacity (J/gK) —
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[2.63 \times 10^{-7} + 2(9.13 \times 10^{-9})\,\Delta T + 3(-2.88 \times 10^{-11})\,\Delta T^2 + \frac{1.09 \times 10^{-6} + 2(1.4 \times 10^{-9})\,\Delta T}{\lambda - 0.26}\right] \Delta T = T - T_0, \quad T_0 = 23\,°\text{C}$$
Physical Properties
Density (g/cm³) 3.83
Relative Cost —
Mechanical Properties
Young's Modulus (GPa) —
Poisson's Ratio —
Knoop Hardness (kgf/mm²) —
Chemical Resistance
Climatic Resistance 1
Stain Resistance 1
Acid Resistance 1
Alkali Resistance —
Phosphate Resistance —
Notes

Recommended glass type

Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd Compare
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SRMOO4-E Generic Birefringent 1.913456 28.381356
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IRG2 Generic IR 1.891717 29.896648
LAH80 Ohara 1.885 30.163795
L-LAH86 Ohara 1.902699 31.00532
H-ZLAF75A CDGM 1.90366 31.31497
N-LASF46A Schott 1.90366 31.32
N-LASF46B Schott 1.90366 31.32
S-LAH95 Ohara 1.903659 31.343065
Similar Glasses (Hoya)
Glass Manufacturer nd Vd Compare
TAFD20 Hoya 1.90315 29.835563
FDS24 Hoya 1.92119 23.96
FDS24-SW Hoya 1.92119 23.96
FDS24-W Hoya 1.92119 23.96
TAFD25 Hoya 1.90366 31.32
TAFD25L Hoya 1.90366 31.32
TAFD21 Hoya 1.9326 27.921009
NBFD30 Hoya 1.85883 30.0
NBFD25 Hoya 1.85451 25.15
FDS1 Hoya 1.922859 20.883457
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