D-K9-25 by CDGM

Preferred Common Precision Molding Environmentally Friendly

D-K9-25 by CDGM is a preferred optical glass with a common melt frequency. It transmits from 0.29 to 2.40 µm with an nd of 1.51577 and a Vd of 63.989637. It has low thermal expansion (CTE of 6.3×10⁻⁶/K), excellent chemical resistance, moderate relative cost, and precision molding compatibility.

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: 0.290–2.400 µm
Optical Properties
Refractive Index (nd) 1.51577
Abbe Number (Vd) 63.989637
Dispersion Formula Sellmeier
Wavelength Range 0.302 — 2.325 µm
$$n(\lambda) = \sqrt{1 + \frac{1.08234\,\lambda^2}{\lambda^2 - 107.908} + \frac{0.548439\,\lambda^2}{\lambda^2 - 0.00219093} + \frac{0.72\,\lambda^2}{\lambda^2 - 0.013407}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 6.3
TCE 100/300°C (10-6/K) 7.8
Thermal Conductivity (W/mK) 1.018
Heat Capacity (J/gK) 0.813
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[4.87 \times 10^{-6} + 2(1.55 \times 10^{-8})\,\Delta T + 3(-1.35 \times 10^{-11})\,\Delta T^2 + \frac{4.17 \times 10^{-7} + 2(5.2 \times 10^{-10})\,\Delta T}{\lambda - 0.177}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 2.41
Relative Cost 4.6
Mechanical Properties
Young's Modulus (GPa) 83.18
Poisson's Ratio 0.212
Knoop Hardness (kgf/mm²) 492.0
Chemical Resistance
Climatic Resistance 1
Stain Resistance —
Acid Resistance —
Alkali Resistance —
Phosphate Resistance —
Notes

anneal rate:25℃/h

Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd Compare
L-BSL7 Ohara 1.51633 64.065129
P-BK7 Schott 1.5164 64.06
S-BSL7R Ohara 1.51633 63.881689
BK7 Sumita 1.51633 64.1
K-BK7 Sumita 1.51633 64.1
S-BSL7 Ohara 1.51633 64.142022
BK7HT Schott 1.51633 64.14348
BSL7 Ohara 1.51633 64.150145
BK7 Schott 1.5168 64.167336
N-BK7 Schott 1.5168 64.17
Similar Glasses (CDGM)
Glass Manufacturer nd Vd Compare
D-K9GT-25 CDGM 1.51577 63.989637
D-K9GT CDGM 1.51633 64.058952
D-K9 CDGM 1.51633 64.058952
H-K9LA CDGM 1.5168 64.198695
H-K9LAGT CDGM 1.5168 64.198695
H-K9LGT CDGM 1.5168 64.198732
H-K9L CDGM 1.5168 64.198732
H-K9L* CDGM 1.5168 64.198732
D-K59 CDGM 1.5176 63.499991
D-K59-25 CDGM 1.51698 63.4085
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