What are the advantages and disadvantages of LiF domes?
Advantages:
High transmittance over a wide band (UV to IR).
Low refractive index for low reflection applications.
High resistance to UV and X-rays.

Disadvantages:
Prone to humidity, need to be used in a dry environment.
Low mechanical strength, easily scratched.

Highly Recommended Optical Domes from Yutai Optics:
Optical Domes
Borosilicate Optical Dome Lens
Sapphire Glass Dome Lens
Infrared Optical Dome Lens
ZnS Optical Dome Lens
MgF2 Optical Dome Lens
Dome with Flange
Visible BK7 Optical Dome Lens
Ultraviolet Fused Silica Optical Dome Lens