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Optical constants of Ge (Germanium)
Icenogle et al. 1976: n 2.5–12 µm; 293 K

Wavelength: µm
 (2.5–12)  
 

Complex refractive index (n+ik)[ i ]


n   k   LogX   LogY   eV

Derived optical constants

Dispersion formula [ i ]

$$n^2-1=8.28156+\frac{6.72880λ^2}{λ^2-0.44105}+\frac{0.21307λ^2}{λ^2-3870.1}$$

Comments

293 K (20 °C)

References

1) Icenogle et al.. Refractive indexes and temperature coefficients of germanium and silicon Appl. Opt. 15 2348-2351 (1976)
2) N. P. Barnes and M. S. Piltch. Temperature-dependent Sellmeier coefficients and nonlinear optics average power limit for germanium J. Opt. Soc. Am. 69 178-180 (1979)
*Ref. 2 provides temperature-dependent Sellmeier equations based on data from Ref. 1.

Data

[Expressions for n]   [CSV - comma separated]   [TXT - tab separated]   [Full database record]

INFO

Germanium, Ge

Germanium is a brittle, lustrous, gray-white metalloid with a diamond-like crystalline structure. While opaque in the visible spectrum, it becomes transparent in the mid-infrared range, from approximately 2 µm to 14 µm. This unique transparency makes germanium highly valuable in the field of infrared optics. It is commonly utilized as a material for lenses, windows, and prisms in thermal imaging systems, as well as a substrate for mid-infrared detectors and emitters. The material is also employed in semiconductor applications, particularly in the production of transistors and photodetectors.Due to its considerable thermal conductivity, it is commonly employed in high-power laser systems. However, its sensitivity to oxidation and high density may pose some limitations for certain applications.

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