Demonstration of a Duplex Microwave Photonic Filter and Its Reconfigurability in a Frequency Range of 0–10 GHz

Abstract

In this paper, we have demonstrated a duplex microwave photonic filter system. The reconfigurability of a microwave passband filter by using a birefringent optical filter has also been demonstrated experimentally. The effect of filtering normally depends on the intermodal separation of a multimode laser diode (MLD), as well as the chromatic dispersion parameter and the length of a Single Mode-Standard Fiber (SM-SF). However, in this work, the intermodal separation of the MLD is altered by an optical filter which consists of a section of birefringent optical fiber (BOF) placed between crossed polarizers. Using this filter, six passbands in the frequency range of 0–10 GHz are obtained. Our duplex Microwave Photonic Filter (MPF) system is driven by only a single optical source. Performance evaluation for the filtered passband is also given in terms of the Signal-to-Noise-Ratio (SNR). On average, an SNR of 13.87 dB is obtained for all the passbands generated by our duplex Microwave Photonic Filter (MPF) system. For potential applications, the generated passbands may be used as radio frequency (RF) carriers to transmit analog or digital data in an optical communications system.