Broadening the angular tolerance in two-dimensional grating resonance structures at oblique incidence

    Authors

    S. Boonruang; A. Greenwell;M. G. Moharam

    Comments

    Authors: contact us about adding a copy of your work at STARS@ucf.edu

    Abbreviated Journal Title

    Appl. Optics

    Keywords

    COUPLED-WAVE ANALYSIS; REFLECTION FILTERS; IMPLEMENTATION; Optics

    Abstract

    Broadening of the angular response of two-dimensional (M) guided mode resonant spectral filters at oblique incidence is investigated. Coupling into multiple fundamental guided resonant modes having the same propagation constant but propagating in different planes (inherent multiple-plane diffraction by 2D gratings) is shown to significantly broaden the angular tolerance while maintaining narrow linewidth. Resonances have symmetric and broad angular responses when the incident wave is coupled to four resonant modes in a structure with a hexagonal grating pattern. Further broadening is implemented by enhancing the second Bragg diffraction of the 2D grating structure. Resonance with a narrow spectral linewidth (Delta lambda(FWHM) similar to 1.6 x 10(-4)lambda(o)) and angularly tolerant to an similar to 6 mu m beam diameter is obtained. A second approach utilizing a dual 2D grating configuration with a second grating on the substrate side is shown to increase the lateral confinement, causing the merging of two successive resonant bands. This results in further improvement of the angular/spectral linewidth ratio by similar to 80%. (C) 2007 Optical Society of America.

    Journal Title

    Applied Optics

    Volume

    46

    Issue/Number

    33

    Publication Date

    1-1-2007

    Document Type

    Article

    Language

    English

    First Page

    7982

    Last Page

    7992

    WOS Identifier

    WOS:000251830400003

    ISSN

    1559-128X

    Share

    COinS