Exploiting spatio-spectral aberrations for rapid synchrotron infrared imaging

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.

Single-shot mid-infrared incoherent holography using Lucy-Richardson-Rosen algorithm

“…Another approach is the Lucy-Richardson algorithm (LRA), which consists of a forward convolution between the initial guess solution and the PSF, which is compared with the recorded OH and the ratio is backward cross-correlated with the PSF and the result is multiplied to the initial guess. This process is iterated until the maximum likelihood object function is reconstructed 23,24 . The (n+1) th reconstructed image is given as…”

Single Shot Lensless Interferenceless Phase Imaging of Biochemical Samples Using Synchrotron near Infrared Beam

“…In recent years, novel imaging experiments have been attempted beyond the physical boundaries using the IRM system at the Australian Synchrotron [ 3 , 4 , 5 ]. A single shot 3D semi-synthetic imaging technique has been demonstrated recently at the IRM beamline using the FPA-FTIR imaging system, with synchrotron source, and a computational algorithm to exploit the spatio-spectral aberrations [ 3 ].…”

“…In recent years, novel imaging experiments have been attempted beyond the physical boundaries using the IRM system at the Australian Synchrotron [ 3 , 4 , 5 ]. A single shot 3D semi-synthetic imaging technique has been demonstrated recently at the IRM beamline using the FPA-FTIR imaging system, with synchrotron source, and a computational algorithm to exploit the spatio-spectral aberrations [ 3 ]. However, the experimental demonstration of a single shot 3D imaging using synchrotron beam is challenging due to the unique nature of the synchrotron-IR beam consisting of a fork shaped intensity distribution.…”

Single Shot Lensless Interferenceless Phase Imaging of Biochemical Samples Using Synchrotron Near Infrared Beam

“…In the recent years, novel imaging experiments have been attempted beyond the physical boundaries using the IRM system at the Australian Synchrotron [3][4][5]. A single shot 3D semi-synthetic imaging technique has been demonstrated recently at the IRM beamline using the offline FPA-FTIR imaging system, with synchrotron source, and a computational algorithm to exploit the spatio-spectral aberrations [3].…”

“…In the recent years, novel imaging experiments have been attempted beyond the physical boundaries using the IRM system at the Australian Synchrotron [3][4][5]. A single shot 3D semi-synthetic imaging technique has been demonstrated recently at the IRM beamline using the offline FPA-FTIR imaging system, with synchrotron source, and a computational algorithm to exploit the spatio-spectral aberrations [3]. However, the experimental demonstration of a single shot 3D imaging using synchrotron beam is challenging due to the unique nature of the synchrotron-IR beam consisting of a fork shaped intensity distribution.…”