We have designed and for the first time experimentally verified a topology optimized mode (de)multiplexer, which demultiplexes the fundamental and the first order mode of a double mode photonic wire to two separate single mode waveguides (and multiplexes vice versa). The device has a footprint of ~4.4 μm x ~2.8 μm and was fabricated for different design resolutions and design threshold values to verify the robustness of the structure to fabrication tolerances. The multiplexing functionality was confirmed by recording mode profiles using an infrared camera and vertical grating couplers. All structures were experimentally found to maintain functionality throughout a 100 nm wavelength range limited by available laser sources and insertion losses were generally lower than 1.3 dB. The cross talk was around -12 dB and the extinction ratio was measured to be better than 8 dB.

Date Published: 27 February 2015
PDF: 9 pages
Proc. SPIE 9367, Silicon Photonics X, 93670X (27 February 2015); doi: 10.1117/12.2078732

Published in SPIE Proceedings Vol. 9367:
Silicon Photonics X
Graham T. Reed; Michael R. Watts, Editor(s)