Pluggable photonic circuit platform for single-mode waveguide connections using novel passive alignment method

Abstract

We describe a novel photonic circuit platform and a method for its passive alignment that will allow pluggable and large-scale multi-chip integration for highly functional single-mode waveguides based on planar lightwave circuit (PLC) chips. We achieve our proposed passive alignment method by employing precise mechanical interdigitation between optical fiber based spacers and dry etched rectangular grooves in silica-based PLCs. The method was applied to a PLC–PLC connection device in which two daughter PLC chips were mounted on a mother PLC chip. The assembled device successfully yielded a low connection loss of less than 0.4 dB for all 16 ports with an extremely simple assembly process. We also determined the alignment accuracy of our method by measuring and calculating the connection losses of an assembled Vernier pitch device. The estimated results show that our passive alignment method efficiently provides high alignment accuracy with submicron accuracy.