Applications of Silicon Nanophotonics: Space-division Multiplexing and Integrated Spectroscopy

A. Grieco, B. Hong, G. Porter, Y. Fainman
University of California, San Diego,
United States

Keywords: integrated optics, distributed Bragg reflectors, space-division multiplexing


Data center needs are evolving as more advanced optical transmission techniques are deployed. This presentation discusses recent technological developments pertaining to the scalability and characterization of the network fabric: space-division multiplexing on a chip, and integrated spectroscopy. Integrated space-division multiplexing (SDM) on a chip partitions the bandwidth utilizing the orthogonal degrees of freedom of the guided spatial modes in a multi-mode waveguide. This approach is tantalizing because it promises cost, complexity and scalability advantages by augmenting or replacing the existing wavelength-division multiplexing (WDM) technology. We discuss our experimental work on integrated periodically nanostructured resonant couplers that selectively transfer energy between arbitrary modes within a multimode waveguide. This coupler possesses advantages in terms of packing density, bandwidth, and tunability in comparison to alternative SDM schemes. Continuing the theme of datacenter telecommunications, we discuss our work on integrated spectroscopy. An integrated spectral analyzer is particularly interesting in this context, and would be invaluable in many portions of the photonic platform. Potential applications include the measurement of optical signals as well as the characterization of laser transmitters and other photonic link components. Naturally, these measurement needs also extend to intra data center traffic and maintenance of the carrier interface. We also discuss the broader implications of integrated spectroscopy in the chemical, biochemical, and medical fields.