Abstract: The present invention intends to provide a two-dimensional photonic crystal resonator having a high Q-value. The slab-shaped body 21 is provided with cyclically arranged holes 22. The body 21 is divided into three areas 31-33 with the holes 22 arranged with cycle distances of a1 in area 31 and a2 in areas 32 and 33, which is smaller than a1. A waveguide 23 passing through the three areas is formed by linearly eliminating the holes 22. The waveguide 23 thus formed can propagate rays of light within a wavelength band that depends on the cycle distance of the holes 22. The cycle distance of the holes in the area 31 differs from that of the areas 32 and 33, and the wavelength band of the light propagating through the waveguide accordingly differs.

Abstract: An object of the present invention is to provide a two-dimensional photonic crystal which can be used for optical path changeover switches or the like to allow switching of a path. A first area 121 and a second area 122 provided with holes 131 and 132 having a difference in the period and size are created on a body 11, and a main waveguide 15 is formed to obliquely cross a boundary 14 between these areas. A branch waveguide 17 branched from the main waveguide 15 into the first area 121 side is also formed by using a crossing point between the main waveguide 15 and the boundary 14 as a starting point. The second area 122 is heated to change a refractive index of the body within the area, so that a frequency band which can be passed through the main waveguide 15 of the second area 122 is changed.

Abstract: In this electromagnetic wave frequency filter, an electromagnetic wave of a predetermined frequency matching a resonant frequency of a resonator 41 is transmitted from an input waveguide 2 to an output waveguide 3 through the resonator 41, and is outputted from a drop port P31. This filter has an input-waveguide-side reflector 211 and an output-waveguide-side reflector 311, which reflect the electromagnetic wave of the predetermined frequency. The electromagnetic wave frequency filter satisfies the following relation: Qinb/(1?cos ?1)<<Qv, Qinb/(1?cos ?1)=Qinr/(1?cos ?2), ?1, ?2?2N?(N=0, 1, . . .

Abstract: An object of the present invention is to provide a two-dimensional photonic crystal which can be used for optical path changeover switches or the like to allow switching of a path. A first area 121 and a second area 122 provided with holes 131 and 132 having a different in the period and size are created on a body 11, and a main waveguide 15 is formed to obliquely cross a boundary 14 between these areas. A branch waveguide 17 branched from the main waveguide 15 into the first area 121 side is also formed by using a crossing point between the main waveguide 15 and the boundary 14 as a starting point. The second area 122 is heated to change a refractive index of the body within the area, so that a frequency band which can be passed through the main waveguide 15 of the second area 122 is changed.

Abstract: The present invention intends to provide a two-dimensional photonic crystal resonator having a high Q-value. The slab-shaped body 21 is provided with cyclically arranged holes 22. The body 21 is divided into three areas 31-33 with the holes 22 arranged with cycle distances of a1 in area 31 and a2 in areas 32 and 33, which is smaller than a1. A waveguide 23 passing through the three areas is formed by linearly eliminating the holes 22. The waveguide 23 thus formed can propagate rays of light within a wavelength band that depends on the cycle distance of the holes 22. The cycle distance of the holes in the area 31 differs from that of the areas 32 and 33, and the wavelength band of the light propagating through the waveguide accordingly differs.

Abstract: In this electromagnetic wave frequency filter, an electromagnetic wave of a predetermined frequency matching a resonant frequency of a resonator 41 is transmitted from an input waveguide 2 to an output waveguide 3 through the resonator 41, and is outputted from a drop port P31. This filter has an input-waveguide-side reflector 211 and an output-waveguide-side reflector 311, which reflect the electromagnetic wave of the predetermined frequency. The electromagnetic wave frequency filter satisfies the following relation: Qinb/(1?cos ?1)<<QV, Qinb/(1?cos ?1)=Qinr/(1?cos ?2), ?1, ?2?2N? (N=0, 1, . . .