We propose a novel optical fiber-to-waveguide coupler for integrated optical circuits. The proper materials and structural parameters of the coupler, which is based on a slot waveguide, are carefully analyzed using a full-vectorial three-dimensional mode solver. Because the effective refractive index of the mode in a silicon-on-insulator-based slot waveguide can be extremely close to that of the fiber, a highly efficient fiber-to-waveguide coupling application can be realized. For a TE-like mode, the calculated minimum mismatch loss is approximately at , and the mode conversion loss can be less than . The discussion of the present state of the art is also involved. The proposed coupler can be used in chip-to-chip communication.
© 2007 Optical Society of AmericaFull Article | PDF Article