Abstract: A device for crossing optical beams. At least a first input optical waveguide is directed along a first axis, a second optical waveguide is directed along a second axis inclined with respect to the first axis, and a photonic crystal having a regular periodicity in an optical crossing region at the intersection of said first and second axis has, opposite the first and second input waveguides, a first and a second output waveguide to provide for exit beams.

Abstract: A method for guiding electromagnetic radiation by providing a photonic crystal made of a bulk material with a predetermined refractive index and having a periodic array of holes with predetermined radius, and feeding to that region an electromagnetic radiation having a wavelength in the fundamental photonic band and so related to the refractive index of the bulk material, to the radius of the holes and to the period of the array that, starting from an isotropic distribution of the wave vectors within a first angular range that is twice the angular extension of the first irreducible Brillouin zone of the photonic crystal, the corresponding group velocity vectors are rearranged as concerns direction and module so that at least 50% of them become directed within a second angular range that is about one-third of the first angular range and the width at half-maximum of the distribution of the modules of the vectors is lower than about two-thirds of the second angular range.

Abstract: A device for varying the direction of an optical beam. A first waveguide is directed along a first direction, a second waveguide is directed along a second direction different from the first direction, and a bending region is interposed between the first and the second waveguide. The bending region has a photonic crystal having a regular periodicity and at least a first and a second crystal axes substantially aligned with the first and second directions, and a reflecting surface delimiting the photonic crystal and so positioned and oriented as to reflect an optical beam coming from the first waveguide toward the second waveguide.

Abstract: A device for crossing optical beams. At least a first input optical waveguide is directed along a first axis, a second optical waveguide is directed along a second axis inclined with respect to the first axis, and a photonic crystal having a regular periodicity in an optical crossing region at the intersection of said first and second axis has, opposite the first and second input waveguides, a first and a second output waveguide to provide for exit beams.

Abstract: A device for varying the direction of an optical beam. A first waveguide is directed along a first direction, a second waveguide is directed along a second direction different from the first direction, and a bending region is interposed between the first and the second waveguide.

Abstract: A method for guiding electromagnetic radiation by providing a photonic crystal made of a bulk material with a predetermined refractive index and having a periodic array of holes with predetermined radius, and feeding to that region an electromagnetic radiation having a wavelength in the fundamental photonic band and so related to the refractive index of the bulk material, to the radius of the holes and to the period of the array that, starting from an isotropic distribution of the wave vectors within a first angular range that is twice the angular extension of the first irreducible Brillouin zone of the photonic crystal, the corresponding group velocity vectors are rearranged as concerns direction and module so that at least 50% of them become directed within a second angular range that is about one-third of the first angular range and the width at half-maximum of the distribution of the modules of the vectors is lower than about two-thirds of the second angular range.