Optical modulation structure, optical isolator and optical circulator

The invention relates to an optical modulation structure and a related optical isolator and optical circulator. The optical modulation structure comprises an optical waveguide which extends along a first extension direction and is provided with a waveguide modulation section; each group of modulation electrodes comprises a plurality of sub-modulation electrodes which are sequentially arranged along the first extension direction, and each sub-modulation electrode is positioned on the two sides of the corresponding sub-waveguide modulation section in the waveguide modulation section so as to modulate the refractive index of the corresponding sub-waveguide modulation section; wherein the plurality of sub-modulation electrodes in each group of modulation electrodes are suitable for being respectively applied with a plurality of corresponding periodic modulation signals with the same frequency but different phases; and the sub-modulation electrodes at the corresponding positions in the plurality of groups of modulation electrodes are suitable for being applied with a periodic modulation signal with the same phase in the plurality of periodic modulation signals, so that the waveguide modulation section is modulated into a refractive index grating structure which moves along the optical waveguide in time-space and has the refractive index periodically changing.