Optical constants of He (Helium)
Cuthbertson and Cuthbertson 1936: n 0.275–0.546 µm
Wavelength:
µm
(0.2753–0.5462)
Complex refractive index (n+ik)
n
k
LogX
LogY
eV
Derived optical constants
Dispersion formula
$$n-1=\frac{0.014755297}{426.29740-λ^{-2}}$$Conditions & Spec sheet
n_is_absolute: true temperature: 0 °C pressure: 101325 Pa
Comments
Standard conditions: 0 °C, 760 torr (101.325 kPa).
References
1) C. Cuthbertson and M. Cuthbertson. The refraction and dispersion of neon and helium. Proc. R. Soc. London A 135, 40-47 (1936)
2) C. Cuthbertson and M. Cuthbertson. On the refraction and dispersion of neon. Proc. R. Soc. London A 83, 149-151 (1910)
* Ref. 1 doesn't cite gas temperature and pressure. See the earlier publication by the same authors (ref. 2) instead.