Chapter 3: Photorefractive Limits
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Chapter 3 Photorefractive Limits
Lithium Niobate, LiNbO
3
, has an optical transparency range from 320 nm to over
5 µm and can withstand pulsed power densities up to 1 MW/cm
2
. However, short
wavelength operation is limited by photorefractive effects which lead to color
center formation and progressively increasing absorption. Photorefractive
damage is noted by increase scattering and absorption in the optical path along
with gray appearance in the crystal (gray tracking).
Photorefractive limits are a concern in the visible region (400
– 700 nm)
particularly with frequency- doubled lasers.
The lithium niobate crystals in Thorlabs
’ EO modulators are MgO-doped for
increased resistance to photorefractive damage.
