New microwave photonic filter based on a ring resonator including a photonic crystal structure

Microwave photonic filters with a performance not achievable by the conventional RF technology, are currently a hot topic in the field of microwave photonics. In this paper, after a brief review of the state-of-the-art of microwave integrated photonic filters and their application in space engineering, the design of a new band-pass filter configuration based on a ring resonator with a photonic crystal included in the resonant path is proposed. The achieved performance parameters are a full-width-at-half-maximum of 10 pm, a Q-factor of 1.5×105, with an extinction ratio equal to 40 dB, and a maximum ripple less than 0.5 dB, within the wavelength range λ0± FWHM/4 (with λ0= 1550 nm). The ring is in silicon technology and it can be integrated with other optoelectronic/photonic components of the filter through a hybrid approach.