Photonic crystal nanocavity assisted rejection ratio tunable notch microwave photonic filter

TLDR

The growing demand for compact, low‑power, high‑efficiency microwave signal processing motivates the use of photonic integrated circuits, with silicon photonics providing a promising platform for ultracompact microwave photonic signal processing via silicon nanophotonic devices. The study proposes and demonstrates a simple scheme to realize an ultracompact, rejection‑ratio‑tunable notch microwave photonic filter based on a silicon photonic crystal nanocavity with fixed extinction ratio. The filter is realized by modulating the optical carrier with a single phase modulator and coupling it to a silicon photonic crystal nanocavity, enabling tunable rejection ratio. Using a conventional modulation scheme with only a single phase modulator, the rejection ratio of the presented MPF can be tuned from about 10 dB to beyond 60 dB, and the central frequency tunable operation in the high rejection ratio region is also demonstrated experimentally.

Abstract

Abstract Driven by the increasing demand on handing microwave signals with compact device, low power consumption, high efficiency and high reliability, it is highly desired to generate, distribute, and process microwave signals using photonic integrated circuits. Silicon photonics offers a promising platform facilitating ultracompact microwave photonic signal processing assisted by silicon nanophotonic devices. In this paper, we propose, theoretically analyze and experimentally demonstrate a simple scheme to realize ultracompact rejection ratio tunable notch microwave photonic filter (MPF) based on a silicon photonic crystal (PhC) nanocavity with fixed extinction ratio. Using a conventional modulation scheme with only a single phase modulator (PM), the rejection ratio of the presented MPF can be tuned from about 10 dB to beyond 60 dB. Moreover, the central frequency tunable operation in the high rejection ratio region is also demonstrated in the experiment.