Design and Experimental Characterization of an InP Photonic Integrated Circuit Working as a Receiver for Frequency-Modulated Direct-Detection Microwave Photonic Links

摘要

In this work, both the design and experimental characterization of an InP photonic integrated circuit (PIC) working as a receiver for frequency-modulated microwave photonic links (MPWL) are presented. The PIC consists of three ring-assisted Mach-Zehnder interferometer (RAMZI) filters acting together as a complementary frequency discriminator, and includes a high-bandwidth balanced photodiode for on-chip signal detection. This is, to the best of our knowledge, the first PIC of this kind to be integrated in an active platform, and the first to include optical detectors. Designed as linear filter in optical intensity, the chip features SFDR values in the range of 78 dB.Hz~(2/3) and RF gains of -46 dB, partially limited by the high optical coupling losses of our experimental setup. Possible paths for further improvement of link figures of merit are also discussed.