Electro-optical tuning of waveguide embedded Bragg gratings in lithium niobate induced by direct femtosecond laser writing

Direct integration of functional optical devices by femtosecond laser writing has emerged as a powerful fabrication technique within recent years. The basic principle relies on strongly localized material modification by nonlinear absorption inside the transparent host material. One of the most attractive features of this technique is the feasibility of producing complex three-dimensional refractive index structures by translating the material relative to the focal point of the writing beam.