Provided is a mode converter for use in optical communication. The mode converter includes a first waveguide, a second waveguide optically coupled into the first waveguide, and omnidirectional reflectors that are disposed on either side of the first waveguide and have forward reflectivity with respect to a mode propagating in the first waveguide. The mode converter provides minimum loss coupling between either optical fiber or low index difference waveguide and a high index contrast waveguide. Furthermore, the mode converter achieves high, bi-directional optical coupling over a wide wavelength range with a simple manufacturing process.