Ultra-High Peak Rejection, Sub-Gigahertz Narrowband and Bandwidth Tunable Microwave Photonic Filter Based on Silicon Racetrack Resonators

• DOI: 10.1109/jlt.2023.3269083
• Publication Date: 2023-04-21T18:18:54Z
• Authors: Li Liu; Shasha Liao
• Keywords: Narrowband; Extinction ratio; Free spectral range

We propose and experimentally demonstrate a notch microwave photonic filter (MPF) with optimized performance (including the sub-gigahertz narrowband, ultra-high rejection ratio tunable bandwidth) based on two cascaded silicon Mach–Zehnder interferometers (MZI) coupled microring resonators (MRRs). The MRR structure is to obtain high quality (Q) factor (corresponding 3dB-bandwidth), adjustable bandwidths extinction ratios. One ring designed as over-coupled state π resonant peak phase shift while other performs under-coupled 0 shift. Under intensity modulation, an extremely MPF could be obtained capitalizing complete interference cancellation technology. Moreover, bandwidth central frequency flexibly tuned by adjusting wavelengths, respectively. experimental results response narrow 3dB-bandwidth of 185 MHz, beyond 70 dB tuning range from MHz 1.263 GHz. To best our knowledge, it first time realize silicon-based narrowband MPFs (>70 dB) gigahertz level. proposed silicon-on-insulator-based competitive paves way for on-chip high-quality signal processing.