BSM81 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) 1.639999
Abbe Number (Vd) 60.091709
Dispersion Formula Schott
Wavelength Range 0.334 — 2.325 µm
$$n(\lambda) = \sqrt{2.64931 - 0.014491\,\lambda^2 + 0.0143906\,\lambda^{-2} + 0.000529455\,\lambda^{-4} - 4.13459 \times 10^{-5}\,\lambda^{-6} + 2.29512 \times 10^{-6}\,\lambda^{-8}}$$
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
LACL6 Hoya 1.640003 60.153568
N-LAK21 Schott 1.64049 60.1
LAK21 Schott 1.640495 60.101885
LAKN2 Sumita 1.6405 60.1
K-LaKn2 Sumita 1.6405 60.1
C41-60 Corning 1.640495 60.130957
LACL60 Hoya 1.64 60.2
H-LAK4L CDGM 1.64 60.202769
LAKL21 Schott 1.64048 59.749915
LAK6 Sumita 1.6425 58.1
Similar Glasses (Ohara)
Glass Manufacturer nd Vd
S-BSM81 Ohara 1.639999 60.078127
S-BSM36 Ohara 1.642495 58.369399
BSM36 Ohara 1.642495 58.369399
S-LAL7 Ohara 1.651597 58.550655
S-LAL7Q Ohara 1.6516 58.544459
LAL7 Ohara 1.651597 58.519433
BSM16C Ohara 1.62041 60.254106
BSM16 Ohara 1.62041 60.271913
S-BSM16 Ohara 1.620411 60.289582
S-BSM15 Ohara 1.622992 58.165763
Compare Glasses