Title: Recent Advances in Astrophotonics: Sophisticated Filters, Spectrometers, and Interferometers on a Chip
Abstract: Astrophotonics is the application of versatile photonic technologies to channel, manipulate, and disperse guided light from one or more telescopes to achieve scientific objectives in astronomy in an efficient and cost-effective way. Utilizing the photonic advantage for astronomical spectroscopy is a promising approach to miniaturize the next generation of spectrometers for ground- and space-based telescopes. In this talk, we will discuss the latest results from our effort to develop in-house photonic near-infrared (1.0 - 1.7 micron) spectrometers where the dispersing optics are replaced by miniature (~ 1 centimeter-square) arrayed waveguide gratings imprinted using buried silicon nitride ("nano-core") technology, the leading solution for low-loss waveguides (throughput > 50%). We have also developed highly sophisticated photonic filters using complex waveguide Bragg gratings, produced on the same platform technology as the photonic spectrometers and equally small. Finally, in recent years, we have also fabricated cascaded multi-mode interferometers on-a-chip that act as nulling interferometers with extinction ratios of 30-60 dB. These novel filters, spectrometers, and interferometers offer a wide range of possible astronomical applications, from spectroscopic studies of the distant universe to searches for biosignatures in the atmospheres of exoplanets.
About the speaker: Sylvain Veilleux is a Professor of Astronomy at the University of Maryland. Born in Montreal, Canada, he received his bachelor’s degree from the University of Montreal (B.Sc. in physics; 1984). He then moved to the United States and got his Ph.D. in 1989 from the University of California, Santa Cruz. He spent his postdoctoral years first as a NSERC Fellow (1989–1992) at the Institute for Astronomy in Hawaii, and then as an Edwin P. Hubble Fellow (1992–1995) at the National Optical Astronomy Observatory (NOAO) in Tucson. In 1995, he joined the Maryland faculty as an assistant professor. He was promoted to associate professor with tenure in 2000 and to full professor in 2005. He has been the Optical Director at Maryland since 2003. He is also a Fellow of the Joint Space-Science Institute, a partnership between the University of Maryland and the NASA Goddard Space Flight Center (GSFC), and a life-time member of Clare Hall, University of Cambridge.