E-FD7 by Hoya

Special Rare Environmentally Friendly

E-FD7 by Hoya is a special optical glass with a rare melt frequency. It transmits from 0.36 to 1.55 µm with an nd of 1.6398 and a Vd of 34.57. It has medium thermal expansion (CTE of 8.7×10⁻⁶/K) and excellent chemical resistance.

Refractive Index vs Wavelength
Refractive Index Calculator
Valid range: 0.36501–1.5296 µm
dn/dλ vs Wavelength
dn/dλ Calculator
Valid range: 0.36501–1.5296 µm
Abbe Number Calculator
Transmission vs Wavelength
Transmission Calculator
Valid wavelength range: 0.360–1.550 µm
Optical Properties
Refractive Index (nd) 1.6398
Abbe Number (Vd) 34.57
Dispersion Formula Schott
Wavelength Range 0.36501 — 1.5296 µm
$$n(\lambda) = \sqrt{2.61659 - 0.0114279\,\lambda^2 + 0.0225344\,\lambda^{-2} + 0.00155129\,\lambda^{-4} - 0.000117699\,\lambda^{-6} + 1.24019 \times 10^{-5}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 8.7
TCE 100/300°C (10-6/K) 10.7
Thermal Conductivity (W/mK) —
Heat Capacity (J/gK) —
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[3.8611 \times 10^{-7} + 2(0)\,\Delta T + 3(0)\,\Delta T^2 + \frac{0 + 2(0)\,\Delta T}{\lambda - 0}\right] \Delta T = T - T_0, \quad T_0 = 23\,°\text{C}$$
Physical Properties
Density (g/cm³) 2.75
Relative Cost —
Mechanical Properties
Young's Modulus (GPa) —
Poisson's Ratio —
Knoop Hardness (kgf/mm²) —
Chemical Resistance
Climatic Resistance 1
Stain Resistance 1
Acid Resistance 1
Alkali Resistance —
Phosphate Resistance —
Notes

Not in a position to accept new order because of discontinuation.

Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd Compare
SF7 Sumita 1.6398 34.6
PBM27 Ohara 1.639799 34.477127
S-TIM27 Ohara 1.639799 34.466422
H-F51 CDGM 1.6398 34.46457
C37-35 Corning 1.636493 35.322642
F6 Schott 1.636359 35.341176
PBM6 Ohara 1.636358 35.376536
F7 CDGM 1.636365 35.386204
S-TIM6 Ohara 1.636358 35.391923
F6 Sumita 1.63636 35.4
Similar Glasses (Hoya)
Glass Manufacturer nd Vd Compare
FD7 Hoya 1.639803 34.568909
F6 Hoya 1.636356 35.340304
E-FD2 Hoya 1.64769 33.84
FD2 Hoya 1.647693 33.836872
FD12 Hoya 1.648308 33.793909
FD9 Hoya 1.654462 33.717017
F7 Hoya 1.625363 35.583498
E-F1 Hoya 1.62588 35.74
F1 Hoya 1.62588 35.744525
F11 Hoya 1.620962 35.947308
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