<title>Micro- and nanoscale domain engineering in lithium niobate and lithium tantalate</title>

Abstract

We present detail investigation of the domain evolution in lithium niobate and lithium tantalate during backswitched electric field poling which allowed to produce micro- and nanoscale domain patterns by applications of voltage to lithographically defined strip electrodes. In situ optical observation of the domain kinetics during poling and high- resolution visualization by SEM and SFM of the static domain patterns on polar surfaces and cross-sections have been used. We separated and studied the main stages of domain evolution. The important role of backswitching as a powerful tool for high-fidelity domain patterning in thick wafers and for production of quasi-periodic nanoscale domain patterns has been demonstrated. We have proposed several variants of domain manipulation during backswitched poling: the frequency multiplication of the domain patterns, domain 'erasing' and 'splitting', formation of oriented arrays of nanoscale domains. We have demonstrated the production of lamellar domain patterns with period down to 2.6 microns in 0.5-mm-thick wafers and strictly oriented quasi-periodic domain arrays consisting of the individual nanodomains with diameter down to 30 nm and density up to 100 per square micron.