The next Imaging and Optical Physics seminar (the last for 2017) will take place at 11 am, Tuesday, 31 October 2017, at Conference Room (Room 760), level 7, David Caro building, Parkville Campus, The University of Melbourne (cnr Swanston Street and Tin Alley).
11 am – 11:30 am. Dr. Nick Phillips (La Trobe University)
Title of the talk: Bragg Coherent Diffractive Imaging and Ptychography
Abstract: Bragg coherent diffractive imaging (BCDI) and ptychography each provide a unique view of nanoscale sample features. Whereas BCDI has traditionally been limited to the study of finite crystalline systems, ptychography has been largely developed for the imaging of extended, non-periodic objects. Recently attempts have been made to combine both techniques to enable the recovery of the spatially resolved lattice displacements in extended crystals. Here I will discuss the latest developments in both these techniques and the challenges and current progress in realising BCDI ptychography.
11:30 pm – 12 noon. Dr. Tim Gureyev (The University of Melbourne)
Title of the talk: On the "unreasonable" effectiveness of Transport of Intensity imaging and optical deconvolution
Abstract: The effectiveness of reconstructive imaging using the Homogeneous Transport of Intensity equation may be regarded as “unreasonable”, because it has been shown to significantly increase signal-to-noise ratio (SNR) while preserving spatial resolution, compared to equivalent conventional absorption-based imaging techniques at the same photon fluence. This outcome seemingly contradicts the noise-resolution uncertainty principle which effectively states that, when the photon fluence (radiation dose) is fixed, the ratio of SNR to noise must be invariant with respect to any linear filtering. We reconcile this surprising behaviour by analysing the propagation of noise in typical in-line holography experiments. This analysis indicates that novel imaging techniques may be designed which produce high signal-to-noise images at low radiation doses without sacrificing spatial resolution.
12 noon – 12:30 pm. Other topics of interest and discussion
Plans and suggestions for the IOP meetings in 2018
