Modified Hamming function weighted waveguide structure for the broadband and minimized mismatched switching couplers

We numerically investigate a new function modified from Hamming function to apply in weighting the waveguide structure of a mismatched switching coupler with the characteristics of low crosstalk, short length, and broad bandwidth. After the numerical design of waveguide structure parameters, the M-HWF waveguide with the shortest coupling length of 4.5 mm can reach a broader bandwidth within 1.50∼1.70 µm.