Abstract

Degradation of lithium niobate integrated optical device performance due to the reversal of ferroelectric micro-domains in localized regions has been described in Ref. 1. However, it has been assumed that these reversals can take place only at extremely high temperatures (near the Curie point) or with very high applied electric fields. Indeed, it has been shown theoretically (Ref. 2) that for pure lithium niobate at room temperature, an electric field of about 3 × 10 9 V/m applied along the crystalline c axis would be necessary to cause domain reversal. Titanium diffusion at elevated temperatures was identified in Ref. 1 as the cause of these reversals and usage of -Z-cut substrates rather than +Z-cut substrates was proposed to reduce their occurrence.

© 1988 Optical Society of America