The guided modes lying in the upper gap-edge band in the photonic band structure of photonic crystals have negative values of refractive index. This feature generates many interesting optical phenomena, and some spectacular photonic devices such as focusing slabs have been developed. We report the design of a photonic-crystal, planoconcave lens for focusing incident parallel light, and theoretically analyze the chromatic aberrations for TM and TE modes. In addition to dielectric photonic crystals, the chromatic aberration of a magnetic photonic-crystal planoconcave lens was investigated because the magnetic permeability may also contribute to the periodic index contrast in photonic crystals, especially at long wavelengths. A significant difference was found in the chromatic aberration for a TM mode propagating in a dielectric than in a magnetic photonic-crystal planoconcave lens.
© 2006 Optical Society of America
Optical Design and Fabrication
Original Manuscript: June 24, 2005
Revised Manuscript: September 11, 2005
Manuscript Accepted: September 30, 2005
Shieh-Yueh Yang, Chin-Yih Hong, and Hong-Chang Yang, "Focusing concave lens using photonic crystals with magnetic materials," J. Opt. Soc. Am. A 23, 956-959 (2006)