OPTICAL ELEMENT AND DEMULTIPLEXER

摘要

PROBLEM TO BE SOLVED: To provide an optical element which is capable of switching photonic band structure dynamically or is capable of performing the switching operation and a demultiplexer using an optical waveguide in a photonic crystal. SOLUTION: This optical element uses plural optical media whose refractive indexes are changed by an external field and certain two refractive indexes among plural optical media are made to become equal or are made to become roughly equal under the certain condition of the external field. The optical element can perform the switching operation between two largely different photonic structure dynamically only by changing the condition of the external field by setting a distribution pattern which is to be sensed by the light to desired crystal structure, the desired shape of a lattice point and a desired cycle under these two conditions.