Lithium Fluoride (LiF)

Lithium Fluoride has high transmittance in the UV region (120nm - 400nm) and is used in a range of components in UV-sources, receivers and eximer lasers. Windows, polarizers and lenses benefit from LiF as a substrate.

Care should be taken with LiF material due to its weakness when expeosed to sudden changes in temperature. Non-standard AR coatings are used when coating LiF material.

Roditi's optical LiF material is single-crystal optical quality, fabricated to order.

Substance Form Diameter Range Thickness Range Transmission Range (µm) Surface Finish
Lithium Fluoride Single Crystal 5mm - 250mm 1 - 100mm 0.12 - 6.00 Fine Ground / Optical Polish

Material Properties

Transmission Range 0.12 - 6.0 microns
Refractive Index 1.3920 @ 0.6 microns
Reflection Loss 5.2% @ 0.6 µm (2 surfaces)
Absorption Coefficient 5.9 x 10-3/cm @ 4.3µm
Density 2.64 gm/cc
Melting Point 855°C
Poisson Ratio 0.324 (calculated)
Hardness 102 Knoop, approx. 3. - 3.5 Mohs
Crystal Structure Cubic <100> cleavage plane
Thermal Expansion Coefficient 37 x 10-6/K