ELECTROMAGNETIC WAVE-SURFACE POLARITON CONVERSION ELEMENT

摘要

PROBLEM TO BE SOLVED: To provide an electromagnetic wave-surface polariton conversion element having steep wavelength selectivity and steep radiation angle or incidence angle selectivity.SOLUTION: An electromagnetic wave-surface polariton conversion element capable of converting an electromagnetic wave into surface polariton has: a base 2 generating surface polariton on its surface; a diffraction grating layer 4 receiving or radiating an electromagnetic wave and having refractive indices periodically changing along at least one first direction perpendicular to a thickness direction; and a spacer layer 3 interposed between the base 2 and the diffraction grating layer 4. An evanescent wave is generated on a boundary face 14 between the diffraction grating layer 4 and the spacer layer 3, and the evanescent wave and the surface polariton generated on a surface 12 of the base 2 are resonated via an electromagnetic wave existing in the spacer layer 3.