Abstract
We demonstrate a robust, compact and low-loss four-channel wavelength-division
multiplexing (WDM) filter based on cascaded double-ring resonators (2RR) in
silicon. The flat-top channel response obtained by the second-order filter
design is exploited to compensate for the detrimental effects of local fabrication
variations and their associated phase errors on the ring-based filter response.
Full wafer-scale characterization of a cascaded, four-channel 2RR filter with
channel spacing of 300 GHz shows an average worst-case insertion loss below
1.5 dB and an average worst-case crosstalk below
$-$
18 dB across the wafer, representing
a substantial improvement over a first-order based ring (1RR) design. The
robust 2RR filter design enables the use of a simple collective thermal tuning
mechanism to compensate for global fabrication variations as well as for global
temperature fluctuations of the WDM filter, the WDM laser source, or both.
Highly uniform collective heating is demonstrated using integrated doped silicon
heaters. The compact filter footprint of less than
$50\times 50\ \mu{\rm m}^{2}$
per channel
enables straightforward scaling of the WDM channel count to 8 channels and
beyond. Such low-loss collectively tuned ring-based WDM filters can prove
beneficial in scaling the bandwidth density of chip-level silicon optical
interconnects.
© 2013 IEEE
PDF Article
More Like This
Cited By
You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
Contact your librarian or system administrator
or
Login to access Optica Member Subscription