Designing low transmission loss silicon slot waveguide at wavelength band of high material absorption

The transmission loss of silicon slot waveguide is investigated by numerical simulation. With the proper designing, the silicon slot waveguide could operate within the wavelength band of high material absorption, i.e., 800–1100 nm. The minimum propagation loss can be as low as 0.05 dB/mm with optimized structural parameters. Furthermore, a linear relation between the slot width and the operating wavelength is found after optimization, which provides a convenient method to design low-loss slot waveguide.