Programmable optical chips for integrated microwave photonics RF filters

Abstract

Programmable optical chips are a key technology for integrated microwave photonics. They enable flexible and stable signal processing operations on miniaturized chips with ultimate control precision and potential for low-cost fabrication. Integrated microwave photonic filters are an important function for photonic-assisted RF front-ends which opens a path to overcome the bandwidth limitation of the current digital electronics. Programmable optical chips enable such filters with high function flexibility, continuous tunability, and sharp frequency selectivity, which facilitate innovations of a wide range of new applications. Here, we review the recent works in this area that pave the path towards realizing microwave photonic filters with DSP-level flexibility, MHz-level frequency selectivity, and very importantly, full function integration on a chip scale.