Fabrication of high-performance lithium niobate photonic integrated circuits using laser microtrimming

Two methods for correction of integrated optical circuits on lithium niobate via laser micro-trimming are proposed. The first method induces changes in the refractive index in waveguides, the second method causes and affects losses in them. The influence of both methods on waveguide elements of integrated intensity modulators is experimentally studied. Increases in the modulators extinction ratio by 17 dB (from 30 to 47 dB) for the first method and by 12 dB (from 28 to 40 dB) for the second method are obtained.