Slab-Modulated Sidewall Bragg Gratings in Silicon-on-Insulator Ridge Waveguides

A slab-modulated sidewall Bragg grating realized by periodically structural corrugation in the sides of silicon slab is demonstrated on a silicon-on-insulator ridge waveguide. Based on this structure, narrow bandwidth can be accurately controlled by varying the distance between the slab grating region and the ridge with high fabrication tolerance. And low side lobes can also be conveniently achieved by changing the extent of sidewall grating teeth. Experimental results show that bandwidths of the example devices can be changed from 0.64 to 1.4 nm, which agree well with the simulated results.