Patent ID: 7369734
Filing Date: 2008-05-06
Classification: B82Y,G02B

Abstract:
1. An optical device comprising: a photonic crystal comprising a periodic repetition of an element; and a line-defect waveguide formed in said photonic crystal in the form of a line-shaped defect, said optical device being configured to guide, through said line-defect waveguide, a light having a wavenumber larger than a wavenumber corresponding to an intersection of an even-mode band and an odd-mode band, said even-mode band and odd-mode band being a waveguide band of said line-defect waveguide formed in said photonic crystal, said even-mode band of said line-defect waveguide including two or more inflection points in a wavenumber region larger than a wavenumber corresponding to said intersection of said even-mode band and said odd-mode band, said optical device being configured to guide a light having a frequency in the vicinity of one of said inflection points, and said photonic crystal further comprising an array of circular-shaped patterns disposed in a medium with a predetermined interval, each circular shaped pattern constituting said element and having a radius determined such that a ratio of said radius to said predetermined interval falls in a range of 0.35 or more but not exceeding 0.50, said predetermined interval being a distance measured from a center of a first circular-shaped pattern and a center of a second circular-shaped pattern adjacent to said first circular pattern.