J. of Electromagn. Waves and Appl., Vol. 25, 733–742, 2011 RING SHAPE OUTPUT INTENSITY PROFILE OF A 1D PHOTONIC CRYSTAL MICRO-CAVITY IRRADIATED BY A GAUSSIAN BEAM R. Abdi-Ghaleh † and K. Jamshidi-Ghaleh Department of Physics Azarbaijan University of Tarbiat Moallem, Tabriz, Iran A. Namdar Faculty of Physics University of Tabriz, Tabriz, Iran T. Touhidi Department of Physics Azarbaijan University of Tarbiat Moallem, Tabriz, Iran Abstract—In this paper, transmission spectrum and output intensity profile of a 1D photonic crystal micro-cavity is studied by using the transfer matrix method. It is shown that the transmission spectrum characteristics of the structure irradiated by a Gaussian beam are noticeably different from the plane-wave irradiation transmission spectrum. A ring-shape output intensity profile is observed under irradiation of a common Gaussian beam profile. The various characteristics of output intensity profile are investigated. 1. INTRODUCTION Photonic crystals (PCs) that are introduced first time by Yablonovitch [1] and John [2] are periodic dielectric or metallic struc- tures that are designed artificially to control and manipulate the prop- agation of light. A PC can be made with refractive index modulation of a medium either by arranging a lattice of air holes in the materials Received 22 November 2010, Accepted 1 January 2011, Scheduled 16 January 2011 Corresponding author: Kazem Jamshidi-Ghaleh (k-jamshidi@azaruniv.edu). † Also with Department of Optics and Laser Engineering, Higher Education Complex of Bonab, Bonab, Azarbaijan-e Shargi, Iran.