Multimode interference (MMI)-based optical splitter is designed and experimentally demonstrated on silicon on insulator for on-chip optical interconnect. We have proposed MMI-based 1  ×  2 optical 3-dB splitter having a compact footprint (2.8  ×  27  μm²). The device shows low excess loss of 0.05 dB for TE mode at operating wavelength 1550 nm and <0.45  dB over broad wavelength 1430 to 1675 nm (S–C–L–U band) using eigenmode expansion (EME) method. The proposed MMI-based Mach–Zehnder interferometer structure is implemented for arbitrary power splitting applications having excess loss <1  dB for wavelength range 1520 to 1580 nm. Moreover, the fabrication tolerance of the device is analyzed using the EME method. The proposed device can be used for on-chip optical interconnects in photonic integrated circuits.