Low voltage modulator

A modulator comprising:

• a waveguide comprising a waveguide column consisting of a waveguide material, the waveguide column having a first side and an opposite second side, the first and second sides extending out from a substrate;
• an etched layer disposed between the waveguide column and the substrate, a first side of the etched layer being in a same plane as the first side of the waveguide column and a second side of the etched layer being in a same plane as the second side of the waveguide column;
• a first contact layer (a) disposed on the first side of the waveguide column and the first side of the etched layer and (b) doped with a P-type dopant, wherein the P-type dopant extends from the first contact layer into a first portion of the waveguide column proximate to the first side;
• and
• a second contact layer (a) disposed on the second side of the waveguide column and the second side of the etched layer and (b) doped with an N-type dopant, wherein the N-type dopant extends from the second contact layer into a second portion of the waveguide column proximate to the second side,
• wherein the first contact layer and the second contact layer each consist of one or more materials that are different from the waveguide material.