Wide-band optical mode converters for coupling between fibers and silicon photonic wires with large misalignment tolerance

Abstract

A wideband optical mode converter is presented for coupling between fibers and sub-wavelength silicon photonic wires with large misalignment tolerance. This converter consists of a three-dimensional (3-D) SU-8 taper and silicon inverted nanotapers, which are cascaded and show coupling losses of 2.8 dB and 4.1 dB for the TE-and TM-polarized waves launched from a cleaved single mode fiber. The fiber misalignment tolerance for 3-dB transmittance drop is estimated to be 3μm. © 1983-2012 IEEE.