TWO-DIMENSIONAL PHOTONIC CRYSTAL AND OPTICAL FUNCTIONAL ELEMENT EMPLOYING IT

摘要

A two-dimensional photonic crystal for use in optical course switches capable of switching the course. A first region (121) and a second region (122) where the period or size of voids (131, 132) is different are formed in a body (11), and a main waveguide (15) is formed to intersect the border (14) of these regions obliquely. Furthermore, a branch waveguide (17) branching from the main waveguide (15) to the first region (121) side is formed starting from the intersection of the main waveguide (15) and the border (14). The frequency band capable of passing through the main waveguide (15) in the second region (122) is varied by heating the second region (122) to vary the refractive index of the body in that region. A light having a specific frequency and propagating from the first region (121) side of the main waveguide (15) is selectively taken out from the second region (122) side of the main waveguide (15) or from the branch waveguide (17) without propagating through the main waveguide (15) in the second region (122) depending on presence/absence of heating.