F4 by CDGM
Obsolete
Rare
Environmentally Dangerous
F4 by CDGM is an obsolete optical glass with a rare melt frequency. It transmits from 0.32 to 2.40 µm with an nd of 1.620047 and a Vd of 36.35673. It has medium thermal expansion (CTE of 9.1×10⁻⁶/K), excellent chemical resistance, low relative cost, and dangerous environmental properties.
Refractive Index vs Wavelength
Refractive Index Calculator
dn/dλ vs Wavelength
dn/dλ Calculator
Abbe Number Calculator
Transmission vs Wavelength
Transmission Calculator
Optical Properties
| Refractive Index (nd) | 1.620047 |
|---|---|
| Abbe Number (Vd) | 36.35673 |
| Dispersion Formula | Schott |
| Wavelength Range | 0.365 — 1.014 µm |
$$n(\lambda) = \sqrt{2.55447 - 0.00847848\,\lambda^2 + 0.0232833\,\lambda^{-2} + 0.000583809\,\lambda^{-4} + 2.1963 \times 10^{-5}\,\lambda^{-6} + 1.96538 \times 10^{-6}\,\lambda^{-8}}$$
Thermal Properties
| TCE -30/70°C (10-6/K) | 9.1 |
|---|---|
| TCE 100/300°C (10-6/K) | 11.4 |
| Thermal Conductivity (W/mK) | — |
| Heat Capacity (J/gK) | — |
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[-2.9 \times 10^{-6} + 2(2.24 \times 10^{-8})\,\Delta T + 3(-2.95 \times 10^{-11})\,\Delta T^2 + \frac{9.73 \times 10^{-7} + 2(8.74 \times 10^{-10})\,\Delta T}{\lambda - 0.246}\right]
\Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Mechanical Properties
Chemical Resistance
| Climatic Resistance | 1 |
|---|---|
| Stain Resistance | — |
| Acid Resistance | — |
| Alkali Resistance | — |
| Phosphate Resistance | — |
Similar Glasses (Other Manufacturers)
| Glass | Manufacturer | nd | Vd | Compare |
|---|---|---|---|---|
| F2HTi | Schott | 1.62004 | 36.37 | |
| F2 | Schott | 1.62004 | 36.37 | |
| F2HT | Schott | 1.62004 | 36.37 | |
| F2 | Hoya | 1.62004 | 36.303385 | |
| C20-36 | Corning | 1.62001 | 36.30126 | |
| F2 | Sumita | 1.62004 | 36.3 | |
| E-F2 | Hoya | 1.62004 | 36.3 | |
| N-F2 | Schott | 1.62005 | 36.43 | |
| PBM2Y | Ohara | 1.620041 | 36.269263 | |
| S-TIM2 | Ohara | 1.620041 | 36.263378 |
Similar Glasses (CDGM)
| Glass | Manufacturer | nd | Vd | Compare |
|---|---|---|---|---|
| H-F4 | CDGM | 1.62005 | 36.345886 | |
| F4GTI | CDGM | 1.62005 | 36.430327 | |
| F3 | CDGM | 1.616592 | 36.627394 | |
| H-F3 | CDGM | 1.61659 | 36.651688 | |
| F5 | CDGM | 1.624353 | 35.938411 | |
| H-F5 | CDGM | 1.62435 | 35.923444 | |
| H-F6 | CDGM | 1.62495 | 35.585173 | |
| F13 | CDGM | 1.625884 | 35.713679 | |
| F6 | CDGM | 1.624954 | 35.577816 | |
| H-F13 | CDGM | 1.62588 | 35.698971 |