Provided is an electro-optical modulator, particularly a double layer graphene modulator having an optimized arrangement to provide both a large optical bandwidth and a high optical transmission for light travelling through an optical waveguide of the modulator, wherein at least one of a top and a bottom graphene sheets extends along a X-direction:



above part of the width of the optical waveguide, wherein that part ranges from 50% to 100% of the width of the optical waveguide; or
completely above the whole width of the optical waveguide, and beyond through a respective further projecting portion with a length, along the X direction, of up to 25% of the optical waveguide width.




Provided is also a method for obtaining the electro-optical modulator of the invention.