Short Photonic-Crystal Directional Coupling Optical Switch of Extended Optical Bandwidth Using Flat Dispersion

摘要

A directional coupling optical switch is constructed from a photonic crystal having a wide optical bandwidth. It has flat dispersion, which allows considerable shortening of its length. The switching operation of a directional coupler having flat dispersion and of an ordinary directional coupler are compared, to prove that the device length can be as short as 4.68 |im (50 times shorter than the conventional one), while maintaining the input energy and bandwidth. A 1.17nm optical switch is fabricated, simultaneously shortening the device and extending the optical bandwidth.