Band-pass filter and method for making photonic crystal for the band-pass filter

A band-pass filter comprising:

• a photonic crystal having a local mode that generates a pass band in a stop band formed by Bragg reflection, the photonic crystal including:
• a periodic structure including a low permittivity dielectric member and a plurality of high permittivity dielectric members periodically arranged in the low permittivity dielectric member so that said Bragg reflection occurs in the periodic structure, and
• a magnetic member disposed in the periodic structure;
• the local mode of electromagnetic waves propagating in the photonic crystal are limited by a transmission channel such that an amplitude direction of an electrical field is a first direction
• a magnetic field-applying unit for applying to the photonic crystal a DC magnetic field in a direction perpendicular to the propagation direction of the electromagnetic waves,
• wherein an electrical length inside the magnetic member is about ½ wavelength at a frequency within the pass band.