Abstract: A coil according to one embodiment of the present invention is a coil in which a first electric wire on an inner peripheral side and a second electric wire on an outer peripheral side are wound side by side to connect ends of the electric wires with each other, and the coil includes a first region where the first electric wire abuts on the second electric wire of another adjacent turn and separates from the second electric wire of a same turn.

Abstract: A coil according to one embodiment of the present invention is a coil in which a first electric wire on an inner peripheral side and a second electric wire on an outer peripheral side are wound side by side to connect ends of the electric wires with each other, and the coil includes a first region where the first electric wire abuts on the second electric wire of another adjacent turn and separates from the second electric wire of a same turn.

Abstract: A coil according to one embodiment of the present invention is a coil in which a first electric wire on an inner peripheral side and a second electric wire on an outer peripheral side are wound side by side to connect ends of the electric wires with each other, and the coil includes a first region where the first electric wire abuts on the second electric wire of another adjacent turn and separates from the second electric wire of a same turn.

Abstract: In order to supply the optical fiber for attenuating optical signal enable the attenuation amount to become flat in wide wavelength scope, simultaneously adding at least two kinds of dopants for attenuating optical signal over the core and the cladding of the optical fiber. Then, properly adjusting the kind and the concentration of dopants for manufacturing the optical fiber 1 for attenuating optical signal; simultaneously adding the dopant enabling the absorption of optical signal to increase with the wavelength become long and the dopant enabling the absorption of optical signal to decrease with the wavelength become long. As the dopant, it is desired to select at least two kinds of transitional metals from Co, Ni, Cr, V, Fe, Mn, Tb and Tm. Further, as the doped area, it is desired to dope the 6 times of the center portion of the core from the center of the core.

Abstract: In order to supply the optical fiber for attenuating optical signal enable the attenuation amount to become flat in wide wavelength scope, simultaneously adding at least two kinds of dopants for attenuating optical signal over the core and the cladding of the optical fiber. Then, properly adjusting the kind and the concentration of dopants for manufacturing the optical fiber 1 for attenuating optical signal; simultaneously adding the dopant enabling the absorption of optical signal to increase with the wavelength become long and the dopant enabling the absorption of optical signal to decrease with the wavelength become long. As the dopant, it is desired to select at least two kinds of transitional metals from Co, Ni, Cr, V, Fe, Mn, Tb and Tm. Further, as the doped area, it is desired to dope the 6 times of the center portion of the core from the center of the core.