H-LAK4L by CDGM

Preferred Common Environmentally Friendly

H-LAK4L by CDGM is a preferred optical glass with a common melt frequency. It transmits from 0.28 to 2.40 µm with an nd of 1.64 and a Vd of 60.202769. It has low thermal expansion (CTE of 6.0×10⁻⁶/K), average 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: 0.280–2.400 µm
Optical Properties
Refractive Index (nd) 1.64
Abbe Number (Vd) 60.202769
Dispersion Formula Sellmeier
Wavelength Range 0.302 — 2.325 µm
$$n(\lambda) = \sqrt{1 + \frac{0.402313\,\lambda^2}{\lambda^2 - -0.00267679} + \frac{1.24575\,\lambda^2}{\lambda^2 - 0.0131716} + \frac{1.28904\,\lambda^2}{\lambda^2 - 93.3655}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 6.0
TCE 100/300°C (10-6/K) 7.8
Thermal Conductivity (W/mK) 0.82
Heat Capacity (J/gK) 0.651
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[5.4 \times 10^{-7} + 2(1.54 \times 10^{-8})\,\Delta T + 3(-2.02 \times 10^{-11})\,\Delta T^2 + \frac{4.56 \times 10^{-7} + 2(2.91 \times 10^{-10})\,\Delta T}{\lambda - 0.15}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 2.99
Relative Cost 4.6
Mechanical Properties
Young's Modulus (GPa) 109.03
Poisson's Ratio 0.287
Knoop Hardness (kgf/mm²) 634.0
Chemical Resistance
Climatic Resistance 3
Stain Resistance —
Acid Resistance —
Alkali Resistance —
Phosphate Resistance —
Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd Compare
LACL60 Hoya 1.64 60.2
LACL6 Hoya 1.640003 60.153568
C41-60 Corning 1.640495 60.130957
BSM81 Ohara 1.639999 60.091709
LAK21 Schott 1.640495 60.101885
N-LAK21 Schott 1.64049 60.1
K-LaKn2 Sumita 1.6405 60.1
LAKN2 Sumita 1.6405 60.1
S-BSM81 Ohara 1.639999 60.078127
LAKL21 Schott 1.64048 59.749915
Similar Glasses (CDGM)
Glass Manufacturer nd Vd Compare
H-LAK50A CDGM 1.6516 58.403057
H-TK9 CDGM 1.62075 60.299778
H-ZK9B CDGM 1.62041 60.339343
H-ZK9A CDGM 1.620412 60.368242
D-ZK21 CDGM 1.62446 58.207924
D-ZK21-25 CDGM 1.62346 58.115078
H-ZK21 CDGM 1.62299 58.120667
H-ZK7A CDGM 1.61309 60.355862
H-ZK7 CDGM 1.613095 60.614383
H-LAK1 CDGM 1.6595 57.34726
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