Apodization of elliptical-core two-mode fiber acousto-optic filter based on acoustic polarization control

Abstract

We propose and demonstrate a novel apodization technique for an elliptical-core two-mode fiber acousto-optic filter by twisting the fiber and adjusting the acoustic polarization. The sidelobe suppression in the filter spectrum was improved from -9.7 to -15.5 dB. A theoretical analysis that includes acoustic birefringence explains the experimental results with good agreement. (c) 2005 Optical Society of America.