Coatings

The energy in the diffracted light varies with the grating's coating material. It is necessary to use the coating material that is appropriate for the required wavelength. Fig. 10 shows the reflectance characteristics for Aℓ , Aℓ+MgF2, and Au.

Fig. 10  Reflectance of Aℓ, Aℓ+MgF2, and Au

Fig. 10 Reflectance of Aℓ, Aℓ+MgF2, and Au