Abstract We report the first fabrication, by a double proton exchange process (Double Exchange, DE) of planar LiNbO3 waveguides simultaneously presenting high index modifications (δne=0.11 at a wavelength of 632.8 nm) and losses as low as 0.4 dB/cm at the same wavelength. We also demonstrate the possibility of superimposing the DE process with titanium indiffusion (Titanium Indiffusion Double Exchange, TIDE) in order to realise high quality guides supporting both TE and TM modes, useful in phase-matched applications.