Fabrication of a deep polyimide waveguide grating for wavelength selection

Abstract

A deep polyimide waveguide grating with transmission of -21 dB is demonstrated. A simple lithography process is used to fabricate the raised waveguide, including a deeply corrugated holographic grating. To accurately control the grating period, a rotatable optical setup is used to adjust the interference angle for the holographic process. The corrugation fabricated holographically is 80 nm much deeper than that written directly by an electron beam. The waveguide is thus a promising low-cost wavelength selective device that can be applied to metro networks. The design principles of the optimum mode-matching condition and the efficient transmission for such a deep waveguide grating are also discussed in this paper. (C) 2002 Elsevier Science B.V. All rights reserved.