Design of highly-nonlinear horizontal slot waveguide with low and flat dispersion

We present an optimum design of highly-nonlinear horizontal slot waveguides consisting of silicon and silicon nanocrystals with flat dispersion characteristics. Results from numerical simulations show that the nonlinear coefficient of 6600 W−1 m−1 at 1550-nm wavelength and the dispersion values between −150 and 150 ps/nm/km in the S, C, and L bands can be achieved. In addition, when we limit the operating bandwidth to C-band, the most tolerant slot height is 20 nm for the 10 nm fabrication errors of waveguide width and high-index region height.