A good performance 3-dB splitter based on coupling-weighted and velocity-tapered waveguides

A coupling-weighted and velocity-tapered 3-dB splitter with a symmetric triple-mode evolution structure weighted by the Blackman function is analytically and numerically investigated for C+L-band passive optical network applications. The splitter is analyzed by the coupled-mode theory and simulated by the use of three-dimensional finite-difference beam propagation method. It is found that the power uniformity, wavelength dependent loss, excess loss and polarization dependent loss of the proposed 3-dB splitter in the whole C+L-band are better than 2.49×10−3 dB, 0.018 dB, 0.14 dB, and 0.004 dB, respectively. It is evident that the 3-dB splitter can achieve the good performances for C+L-band passive optical network applications.