Photonic integrated circuits for broadband analog signal processing: Progress and challenges

This paper highlights the progress toward the application of PIC technology in high-bandwidth analog signal processing applications based on the use of unit cells as building blocks for high-order filters. The differing performance constraints inherent in the various PIC technologies have lead to differing unit cell and filtering architectures. Future work will focus on defining and implementing the unit cell-based filter architectures needed to implement broad-band programmable high performance channelizers. Key issues will center on the incorporation of control elements that ensure the desired level of programmability and stability for the aggregated PHASER filter architectures.