Performance, analysis and design of microwave photonic spectral domain
filters using optical microcombs
Abstract
Microwave transversal filters, which are implemented based on the
transversal filter structure in digital signal processing, offer a high
reconfigurability for achieving a variety of signal processing functions
without changing hardware. When implemented using microwave photonic
(MWP) technologies, also known as MWP transversal filters, they provide
competitive advantages over their electrical counterparts, such as low
loss, large operation bandwidth, and strong immunity to electromagnetic
interference. Recent advances in high-performance optical microcombs
provide compact and powerful multi-wavelength sources for MWP
transversal filters that require a larger number of wavelength channels
to achieve high performance, allowing for the demonstration of a diverse
range of filter functions with improved performance and new features.
Here, we present a comprehensive performance analysis for
microcomb-based MWP spectral filters based on the transversal filter
approach. First, we investigate the theoretical limitations in the
filter spectral response induced by finite tap numbers. Next, we analyze
the distortions in the filter spectral response resulting from
experimental error sources. Finally, we assess the influence of input
signal’s bandwidth on the filtering errors. These results provide a
valuable guide for the design and optimization of microcomb-based MWP
transversal filters for a variety of applications.