Design of broadband power splitters using two-mode interference in slot waveguides

Two-mode interference effects in slot waveguides have been predicted and investigated through plane wave expansion and finite-difference time-domain methods. A broadband 1×2 power splitter (PS) based on this effect is presented, and its transmission characteristics are investigated by using finite-difference time-domain method. Calculated results indicate that, for the 1×2 PS whose interaction length is as short as 0.509 µm, the high transmission (≥95%) is observed within a wavelength range of 1.389-1.747 µm, corresponding to a relative bandwidth of 22.87%. Combining three 1×2 PS, we construct a 1×4 PS with excellent transmission characteristics. Those simple PS are expected to be applied to highly dense photonic integrated circuits.