Patent ID: 6768575
Filing Date: 2004-07-27
Classification: B82Y,G02B

Abstract:
An optical deflection element for splitting light rays in accordance with a wavelength of incident light, comprising:a photonic crystal having an entrance end face and an exit end face, and having a refractive index which periodically changes depending upon positions thereof, wherein: said element includes a region in which a propagation angle &thgr;C of the incident light within said photonic crystal changes in accordance with the wavelength of the incident light having entered at an incident angle &thgr;IN into the entrance end face so as to split the light rays having different wavelengths in accordance with different beam positions on the exit end face caused by a change of the propagation angle &thgr;C based on the wavelength of the incident light, and a relationship among a wavelength &lgr; of the incident light in vacuum, a lattice constant A of said photonic crystal, the incident angle &thgr;IN and the propagation angle &thgr;C satisfies (âˆ‚&thgr;C/âˆ‚(A/&lgr;))/(âˆ‚&thgr;C/âˆ‚&thgr;IN)>10.