Low Loss All-Silicon Single Mode Optical Waveguide with Small Cross-Section

Abstract

The realization of single-mode rib waveguides in standard epitaxial silicon layer on lightly-doped silicon substrate, using ion-implantation to form the lower cladding, is reported. The waveguides were designed with a cross-section comparable in size to the mode-Weld-diameter of standard single-mode optical Wber, so reducing the Wberwaveguide coupling losses. Propagation losses of about 1.0 dB/cm, for ¶ˆ1.3 ·m, in the single mode regime, have been measured. Numerical evaluation of the theoretical attenuation and the transverse optical Weld proWles has been performed, both for ¶ˆ1.3 ·m and ¶ˆ1.55 ·m. The proposed technique is low-cost, fully compatible with standard very large scale integration (VLSI) processes.