
ring with Q 10 900, an FSR of 450 GHz, and a passband width of 18 GHz, residual
filter insertion loss of <0.5 dB, and transmission bandwidth that is nearly adequate for
10 Gb/s bandwidth. This devices is capable of handling 4 channels separated by
100 GHz while maintaining crosstalk below –20 dB. However, the Lorentzian roll-
off characteristic of a single ring does pose challenges in keeping adequate filter
bandwidth to minimize a link intersymbol interference (ISI) penalty while keeping
adjacent channel crosstalk at a low value.
Higher order, cascaded ring filters have been known to provide flat-top filters
with sharp roll-off characteristics for ...