A tunable photonic RF notch filter based on opto-VLSI technology

In this paper, we propose a novel tunable transversal photonic RF notch filter based on opto-VLSI technology. By using an array of fiber Bragg gratings (FBGs) in conjunction with an opto-VLSI processor, the broadband light source can be spectrally sliced and attenuated, hence realizing a two-tap RF notch filler with stepwise true-time delays and variable weights. In addition, the free spectral frequency and notch depth of the RF notch filter can be tuned by driving the opto-VLSI processor with optimized phase-only holograms. We experimentally demonstrate the proposed tunable RF notch filter structure and the results show that a notch depth greater than 40 dB can be attained.