Si3N4 ring resonator-based microwave photonic notch filter with an ultrahigh peak rejection

摘要

We report a simple technique in microwave photonic (MWP) signal processingthat allows the use of an optical filter with a shallow notch to exhibit amicrowave notch filter with anomalously high rejection level. We implement thistechnique using a low-loss, tunable Si3N4 optical ring resonator as the opticalfilter, and achieved an MWP notch filter with an ultra-high peak rejection > 60dB, a tunable high resolution bandwidth of 247-840 MHz, and notch frequencytuning of 2-8 GHz. To our knowledge, this is a record combined peak rejectionand resolution for an integrated MWP filter.