Abstract: The influence of the width of the slot in the slot ridge waveguide, the width of the waveguide on both sides of the slot, the thickness of the drapped waveguide in the slot on the distribution of the light field in the slot ridge waveguide were studied by FDTD simulation. In the slot ridge waveguide, the normalized optical power firstly increased and then decreased with the increase of the slot width. Similarly, the optical power also increased first and then decreased with the increase of the waveguides on both sides of the slot; with the increase of slot etching depth, the normalized optical power was gradually increased. And the experimental results showed that the normalized optical power reached the maximum 13.54% when the width of the slot was 40 nm, the width of the two sides of the waveguide was 220 nm, and the silicon of the slot was completely etched. The simulation results were expected to optimize the integration of the slit ridge waveguide with the modulator.

Key words: ridge waveguide, light field distribution, optical power, slot, FDTD;dimension