Ge. Betts et al., EFFECT OF ANNEALING ON PHOTOREFRACTIVE DAMAGE IN TITANIUM-INDIFFUSED LINBO(3) MODULATORS, IEEE photonics technology letters, 6(2), 1994, pp. 211-213
We have evaluated photorefractive effects at 1320-nm and 1064-nm optic
al wavelengths in interferometric modulators built using Ti-indiffused
waveguides in lithium niobate. The sensitivity to photorefractive dam
age is substantially increased by anneals in non-oxygen atmospheres at
temperatures greater-than-or-equal-to 200-degrees-C. The sensitivity
can be reduced by an anneal in oxygen. Properly annealed modulators op
erated for 150 h with 400 mW at 1320 nm with no photorefractive effect
s other than a 3-degrees change in bias point.