Domain establishment in periodically poled lithium niobate

Summary form only given. The efficiency of frequency doubling through quasi phase-matching in periodically poled lithium niobate is known to decline as the width of the individual domains approaches a few micrometers. Irregularity in the poled domain configuration appears in two forms, which are correlated with the structural variation that preceded the poling process. Lateral variation in the boundary position between adjacent domains leads to widespread local fluctuation in domain width. In addition to this fluctuation, the extension of sets of adjacent domains is restricted by incidental transverse subgrain boundaries, which cut across domain clusters.