User Meeting 2014

Design and Implementation of an Optical Ptychographic Microscope at La Trobe University

20 Nov 2014, 17:30

1h 30m

NCSS Exhibition Area ()

Board: 1001

Poster Structural Biology Welcome Function, Poster Session, Exhibition

Speaker

Mr Nicholas Anthony (Australian Research Council, Centre of Excellence in Advanced Molecular Imaging, La Trobe University, VIC 3086, Australia)

Description

Ptychography is a method for quantitatively determining the phase of of a samples’ complex transmission function. The technique relies upon the collection of multiple overlapping coherent diffraction patterns from laterally displaced points on the sample. The overlap of measurement points provides complementary information that significantly aids in the reconstruction of the complex wavefield exiting the sample. Moreover the method is sufficiently robust to simultaneously recover both the sample and probe functions from a single dataset. Ptychography was initially realised for applications involving electron microscopy (Hoppe et al., Acta Cryst. A, 1969) but has been widely adopted by the x-ray lensless imaging community. More recently, it has found application in the optical regime (e.g. Godden et al. Optics Express, 2014) where it can be applied to 2D and 3D quantitative phase contrast imaging of weakly interacting specimens. Here we describe and demonstrate the realisation of a high-quality optical ptychographic microscope at La Trobe University comprising ‘off the shelf’ components. As well as providing important proof-of-principle data for developing coherent imaging experiments at synchrotron and X-ray Free Electron Laser (XFEL) sources, we are planning to develop this instrument for applications involving complimentary live cell imaging.