Abstract
A comparative study has been performed between the finite difference time domain technique and the time domain beam propagation method (TD-BPM) while assessing the ultra short pulsed beam propagation inside dispersive power splitter. The dispersive GaAs material, used in the device, is modeled by Lorentzian dispersion relation that satisfies the refractive index of the material at a certain wavelength and shows a strong dispersion over a wide wavelength range. A smarter moving window technique is needed to be applied rather than at pulse's group velocity for the TD-BPM, especially for bifurcated opto-electronic devices at the ultra short pulse.