[Lecture] Phase contrast imaging with nanophotonics
Sep. 23, 2022
Speaker: Ann Roberts, the University of Melbourne
Time: 20:00 pm, September 23, 2022, GMT+8
Venue: iCANX Talks platform (https://www.ican-x.com/talks)
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The real-time visualisation of phase using compact optics remains an ongoing challenge in contemporary optics. It is well-known that the introduction of spatial filters in the Fourier plane of an imaging system can be used to enhance the contrast of images of essentially transparent objects but, as with conventional interferometry, these systems are inherently bulky. Other methods, such as Differential Interference Contrast (DIC) microscopy, that utilise relatively expensive optical components are extremely popular, particularly in the biosciences for imaging live, unstained cells. There also remains strong interest in the development of computational methods for extracting quantitative information about the phase of an optical field with potential applications in imaging and adaptive optics. These traditional approaches, however, are incompatible with the drive for miniaturization of devices for real-time optical imaging, diagnostics and sensing while reducing energy consumption and cost. To address this issue there is an emerging interest in the use of metasurfaces as ultra-compact devices for all-optical image processing. Not only are images generated in real time but require no additional energy. Here we present two nanophotonic strategies for producing phase contrast images in real-time with no subsequent digital processing. One utilises the phenomenon of light ‘routing’ while the other relies on the inherent angular sensitivity of resonant waveguide gratings.
Ann Roberts obtained B.Sc. (Honours) and Ph.D. degrees in physics from the University of Sydney. After a position as a postdoctoral associate in the School of Electrical Engineering at Cornell University, she took up an academic position in the School of Physics at the University of Melbourne. Professor Roberts has diverse research interests in physical optics and photonics. She is a Fellow of the Australian Institute of Physics, the Optical Society and the SPIE and a former President of the Australian and New Zealand Optical Society. Professor Roberts is a Chief Investigator in the ARC Centre of Excellence for Transformative Meta-Optical Systems (TMOS).