Emerging applications of integrated optical microcombs for analogue RF and microwave photonic signal processing

We review new applications of integrated microcombs in RF and microwave photonic systems. We demonstrate a wide range of powerful functions including a photonic intensity high order and fractional differentiators, optical true time delays, advanced filters, RF channelizer and other functions, based on a Kerr optical comb generated by a compact integrated microring resonator, or microcomb. The microcomb is CMOS compatible and contains a large number of comb lines, which can serve as a high performance multiwavelength source for the transversal filter, thus greatly reduce the cost, size, and complexity of the system. The operation principle of these functions is theoretically analyzed, and experimental demonstrations are presented.Comment: 16 pages, 8 figures, 136 References. Photonics West 2018 invited paper, expanded version. arXiv admin note: substantial text overlap with arXiv:1710.00678, arXiv:1710.0861

Harnessing optical micro-combs for microwave photonics

In the past decade, optical frequency combs generated by high-Q micro-resonators, or micro-combs, which feature compact device footprints, high energy efficiency, and high-repetition-rates in broad optical bandwidths, have led to a revolution in a wide range of fields including metrology, mode-locked lasers, telecommunications, RF photonics, spectroscopy, sensing, and quantum optics. Among these, an application that has attracted great interest is the use of micro-combs for RF photonics, where they offer enhanced functionalities as well as reduced size and power consumption over other approaches. This article reviews the recent advances in this emerging field. We provide an overview of the main achievements that have been obtained to date, and highlight the strong potential of micro-combs for RF photonics applications. We also discuss some of the open challenges and limitations that need to be met for practical applications.Comment: 32 Pages, 13 Figures, 172 Reference

Chip-Scale Microwave Photonic Signal Processing

The use of optical technology can provide unprecedented performance to the generation, distribution, and processing of microwave. Recently, on-chip microwave photonics (MWP) has gained significant interests for its numerous advantages, such as robustness, reconfigurability as well as reduction of size, weight, cost, and power consumption. In this chapter, we review our recent progress in ultracompact microwave photonic signal processing using silicon nanophotonic devices. Using the fabricated silicon waveguide, silicon microring resonators (MRRs) and silicon photonic crystal nanocavities, we demonstrate on-chip analog signal transmission, optically controlled tunable MWP filter, and ultra-high peak rejection notch MWP filter. The performance of analog links and the responses of MWP filters are evaluated in the experiment. In addition, microwave signal multiplication and modulation are also demonstrated based on a silicon Mach-Zehnder modulator in the experiment with favorable operation performance. The demonstrated on-chip analog links, MWP filters, microwave signal multiplication/modulation may help understand on-chip analog signaling and expand novel functionalities of MWP signal processing