Tunable SU-8 waveguide grating filter using electrostatic actuation for DWDM optical network

Abstract

In this paper we have designed and simulated a novel tunable filter for DWDM optical network utilizing Bragg wavelength shift of SU-8 waveguide grating located on an electrostatically actuated micromachined cantilever beam. The proposed structure consists of a waveguide Bragg grating located on the cantilever beam. When the beam deflects due to an applied electrostatic force, strain is introduced in the beam and hence the grating period changes giving rise to shift in the Bragg wavelength. Since Bragg gratings acts like filter in transmission spectrum we can achieve tunable filter by applying varying voltages to the cantilever beam. For the chosen dimensions The Full Width Half Maximum (FWHM) achievable was 0.89 nm. We have achieved Bragg wavelength shift of 8.7 nm at 1557.58 nm for 19.5 V actuation providing tuning for 12 DWDM channels.