All-fiber 2/spl times/2 polarization-insensitive switch

Abstract

We have demonstrated a broadband, polarization-independent all-fiber switch. It is based on twisting the waist of a null taper coupler. The polarization sensitivity is reduced from 17 dB to 0.2 dB. The device has a low drive power requirement, low insertion loss and a conversion efficiency of /spl sim/100%. The null coupler is fabricated from standard telecommunications fiber and is, therefore, compatible with any existing network.