A new design for coupling light between silicon strip waveguide and plasmonic slot waveguide
We simulate and test a new structure for light coupling from silicon strip waveguide to plasmonic slot waveguide. The conventional approach of simply using a taper funnel structure for the mode matching between two types of waveguides is typically insufficient for high coupling efficiency. Here we propose the use of an additional silicon strip to slot mode converter, which has a low insertion loss itself and achieves better mode matching. The experimental results show the new design, with slot width fixed at 200nm, achieves a higher coupling efficiency than conventional one. The newly implemented design has 1.5 dB less loss than the conventional taper funnel coupler, with a theoretical coupling loss of 2.18 dB/coupler and an experimentally measured loss of 3 dB/coupler at 1640nm wavelength.
SPIE OPTO