H-BAK5 by CDGM

Standard Rare Environmentally Friendly

H-BAK5 by CDGM is a standard optical glass with a rare melt frequency. It transmits from 0.30 to 2.40 µm with an nd of 1.56069 and a Vd of 58.344731. It has medium thermal expansion (CTE of 7.6×10⁻⁶/K), excellent chemical resistance, and moderate relative cost.

Refractive Index vs Wavelength
Refractive Index Calculator
Valid range: 0.302–2.325 µm
dn/dλ vs Wavelength
dn/dλ Calculator
Valid range: 0.302–2.325 µm
Abbe Number Calculator
Transmission vs Wavelength
Transmission Calculator
Valid wavelength range: 0.300–2.400 µm
Optical Properties
Refractive Index (nd) 1.56069
Abbe Number (Vd) 58.344731
Dispersion Formula Sellmeier
Wavelength Range 0.302 — 2.325 µm
$$n(\lambda) = \sqrt{1 + \frac{0.858086\,\lambda^2}{\lambda^2 - 101.019} + \frac{0.38007\,\lambda^2}{\lambda^2 - 0.0203677} + \frac{1.01788\,\lambda^2}{\lambda^2 - 0.00564516}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 7.6
TCE 100/300°C (10-6/K) 8.8
Thermal Conductivity (W/mK) —
Heat Capacity (J/gK) —
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[1.4 \times 10^{-7} + 2(1.75 \times 10^{-8})\,\Delta T + 3(-3.27 \times 10^{-11})\,\Delta T^2 + \frac{5.66 \times 10^{-7} + 2(4.64 \times 10^{-10})\,\Delta T}{\lambda - 0.16}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 3.01
Relative Cost 3.3
Mechanical Properties
Young's Modulus (GPa) 75.39
Poisson's Ratio 0.243
Knoop Hardness (kgf/mm²) 542.0
Chemical Resistance
Climatic Resistance 1
Stain Resistance —
Acid Resistance —
Alkali Resistance —
Phosphate Resistance —
Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd Compare
BAC5 Hoya 1.556708 58.562365
BAK5 Schott 1.556709 58.649202
BAL15Y Ohara 1.556711 58.679177
BAL15 Ohara 1.556711 58.689461
BAK50 Schott 1.567736 57.990411
BAL11 Ohara 1.572501 57.760854
S-BAL11 Ohara 1.572501 57.74298
K-SKLD300(M) Sumita 1.56124 60.1
N-BAK1 Schott 1.5725 57.55
BAK1 Schott 1.5725 57.54931
Similar Glasses (CDGM)
Glass Manufacturer nd Vd Compare
H-BAK8 CDGM 1.5725 57.486797
H-BAK6 CDGM 1.56388 60.764747
H-BAK7A CDGM 1.568828 56.127804
H-BAK7GT CDGM 1.56883 56.041308
H-BAK7 CDGM 1.56883 56.041308
D-ZK2-25 CDGM 1.58241 59.308255
H-BAK2 CDGM 1.53996 59.724182
D-ZK2A-25 CDGM 1.58229 59.453631
D-ZK2 CDGM 1.58313 59.381686
H-ZK2 CDGM 1.58313 59.460082
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