Prism coupling to on-chip silicon based bragg cladding waveguide

We developed a silicon based asymmetric Bragg cladding waveguide, which is composed of high index contrast Si and Si 3 N 4 clad layers and has omnidirectional reflectivity. Prism coupling was used to demonstrate the guiding mechanism by Bragg reflection. The effective index of the propagation mode was measured directly. The measured effective mode index is less than either the Si or Si 3 N 4 cladding layers, which is a clear demonstration of the Bragg waveguiding principle. Low loss of the Si Bragg cladding waveguide around 0.5 dB ∕ cm for both TE and TM polarizations is achieved. Potential applications include high power transmission, low dispersion, thin cladding thickness, and nonlinear properties engineering on silicon chip.