Low loss membrane-based electro-optic photonic waveguides

International audienceWe report on low-loss vertical tapers for efficient couplingbetween confined LiNbO3 optical ridge waveguides and Single ModeFibers. 3D-Pseudo-Spectral-Time-Domain calculations and Optical-Coherence-Tomography-based methods are advantageously used for thenumerical and experimental study of the tapers. The tapered-section is donesimultaneously with the ridge waveguide by means of a circular precisiondicing saw, so that the fabrication procedure is achieved in only two steps.The total insertion losses through a 1.6 cm long ridge waveguide aremeasured to be improved by 3 dB in presence of the taper. These taperedridgewaveguides open the way to the low-cost production of low-lossphase modulators or resonators