Exploiting spatio-spectral aberrations for rapid synchrotron infrared imaging
Vijayakumar Anand, Soon Hock Ng, Tomas Katkus, Jovan Maksimovic, Annaleise R. Klein, Jitraporn Vongsvivut, Keith R. Bambery, Mark J. Tobin, Saulius Juodkazis
Abstract
The Infrared Microspectroscopy Beamline at the Australian Synchrotron is equipped with a Fourier transform infrared (FTIR) spectrometer, which is coupled with an infrared (IR) microscope and a choice of two detectors: a single-point narrow-band mercury cadmium telluride (MCT) detector and a 64 × 64 multi-pixel focal plane array (FPA) imaging detector. A scanning-based point-by-point mapping method is commonly used with a tightly focused synchrotron IR beam at the sample plane, using an MCT detector and a matching 36× IR reflecting objective and condenser (NA = 0.5), which is time consuming. In this study, the beam size at the sample plane was increased using a 15× objective and the spatio-spectral aberrations were investigated. A correlation-based semi-synthetic computational optical approach was applied to assess the possibilities of exploiting the aberrations to perform rapid imaging rather than a mapping approach.