A tunable 1x4 silicon CMOS photonic wavelength multiplexer/demultiplexer for dense optical interconnects

We report the first compact silicon CMOS 1x4 tunable multiplexer/demultiplexer using cascaded silicon photonic ring-resonator based add/drop filters with a radius of 12 mu m, and integrated doped-resistor thermal tuners. We measured an insertion loss of less than 1dB, a channel isolation of better than 16dB for a channel spacing of 200GHz, and a uniform 3dB pass band larger than 0.4nm across all four channels. We demonstrated accurate channel alignment to WDM ITU grid wavelengths using integrated silicon heaters with a tuning efficiency of 90pm/mW. Using this device in a 10Gbps data link, we observed a low power penalty of 0.6dB. (C) 2010 Optical Society of America