BSM18 by Ohara

Obsolete Unknown Environmentally Dangerous
Refractive Index vs Wavelength
Refractive Index Calculator
Valid range: 0.334–2.325 µm
dn/dλ vs Wavelength
dn/dλ Calculator
Valid range: 0.334–2.325 µm
Abbe Number Calculator
Transmission vs Wavelength

No transmission data available.

Optical Properties
Refractive Index (nd) 1.638539
Abbe Number (Vd) 55.384768
Dispersion Formula Schott
Wavelength Range 0.334 — 2.325 µm
$$n(\lambda) = \sqrt{2.63852 - 0.0109684\,\lambda^2 + 0.015974\,\lambda^{-2} + 0.000535193\,\lambda^{-4} - 3.57057 \times 10^{-5}\,\lambda^{-6} + 2.60354 \times 10^{-6}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K)
TCE 100/300°C (10-6/K)
Thermal Conductivity (W/mK)
Heat Capacity (J/gK)
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[0 + 2(0)\,\Delta T + 3(0)\,\Delta T^2 + \frac{0 + 2(0)\,\Delta T}{\lambda - 0}\right] \Delta T = T - T_0, \quad T_0 = 25\,°\text{C}$$
Physical Properties
Density (g/cm³)
Relative Cost
Mechanical Properties
Young's Modulus (GPa)
Poisson's Ratio
Knoop Hardness (kgf/mm²)
Chemical Resistance
Climatic Resistance
Stain Resistance
Acid Resistance
Alkali Resistance
Phosphate Resistance
Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd
SK18A Schott 1.63854 55.423596
N-SK18 Schott 1.63854 55.423596
H-ZK11 CDGM 1.63854 55.446553
BACD18 Hoya 1.63854 55.45
K-SK18RH Sumita 1.63854 55.5
K-SK18 Sumita 1.63854 55.5
SK18RH Sumita 1.63854 55.5
SK18 Sumita 1.63854 55.5
C39-56 Corning 1.638505 55.504447
M-PCD55AR Hoya 1.63858 55.18
Similar Glasses (Ohara)
Glass Manufacturer nd Vd
S-BSM18 Ohara 1.638539 55.380028
BSM93 Ohara 1.640998 56.927542
S-BSM93 Ohara 1.640998 56.927542
LAL54 Ohara 1.650996 56.154774
S-LAL54 Ohara 1.650996 56.163717
S-LAL54Q Ohara 1.651 56.238379
S-BSM10 Ohara 1.622799 57.052723
BSM71 Ohara 1.648497 53.035185
BSM10 Ohara 1.622799 57.063643
S-BSM71 Ohara 1.648498 53.023881
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