US Patent 9971091 Optical devices and methods for fabricating an optical device

According to various embodiments, there is provided an optical device including: a waveguide configured to propagate an electromagnetic wave, the waveguide including a first grating and further including a second grating; a first further waveguide including a first further grating, the first further waveguide having a first width, wherein the first further grating is coupled to the first grating to form a first pair of coupled gratings, wherein a grating period of the first further grating is at least substantially equal to a grating period of the first grating; a second further waveguide including a second further grating, the second further waveguide having a second width, wherein the second further grating is coupled to the second grating to form a second pair of coupled gratings, wherein a grating period of the second further grating is at least substantially equal to a grating period of the second grating.