David D. Sampson, Timothy R. Hillman, Thomas Gutzler, Abhijit Patil, Sergey A. Alexandrov,. Optical+Biomedical Engineering Laboratory,. School of Electrical ...
(INVITED) Coherent and incoherent spatial frequency domain approaches to widefield characterisation and microscopy David D. Sampson, Timothy R. Hillman, Thomas Gutzler, Abhijit Patil, Sergey A. Alexandrov, Optical+Biomedical Engineering Laboratory, School of Electrical, Electronic, & Computer Engineering, University of Western Australia, Australia
There is an innate compromise between field of view and resolution in microscopy – biological samples, in particular, are often sufficiently large to require many image captures at the necessary resolution. To acquire the third dimension, 3D imaging is most commonly performed sequentially by stepping a focussed beam in an optical sectioning microscope such as the confocal microscope or one based on optical coherence tomography. A very powerful way of understanding such approaches and their strengths and limitations is through the three-dimensional spatial frequency domain representation of their transfer functions, and how these change in response to various variables. We apply this representation to describe our proposed novel coherent and incoherent approaches to high-resolution characterisation and imaging that exploit lownumerical aperture optics and off-axis illumination [1-5]. The coherent approaches are based on Fourier holography, and are capable of characterising angular scattering, generating single-capture 3D images, and exhibit superresolution through an enhanced synthetic aperture. The incoherent approach uses wavelength encoding of spatial frequencies, and is sensitive to nanometer-scale microstructural features over centimetrescale sample areas. These approaches will be compared with their well-established counterparts, confocal microscopy and optical coherence tomography. References 1 2 3 4 5
S. A. Alexandrov, T. R. Hillman, D. D. Sampson, “Spatially resolved Fourier holographic light scattering angular spectroscopy”, Opt. Lett., vol. 30 , no. 24, pp. 3305-3307, 2005. T. R. Hillman, S. A. Alexandrov, T. Gutzler, D. D. Sampson, “Microscopic particle discrimination using spatiallyresolved Fourier-holographic light scattering angular spectroscopy”, Opt. Express, vol. 14, no. 23, pp. 11088-11102, 2006. S. A. Alexandrov, T. R. Hillman, T. Gutzler, D. D. Sampson, “Synthetic aperture Fourier holographic optical microscopy”, Phys. Rev. Lett., vol. 97 , no. 16, 168102, 2006. S. A. Alexandrov, T. R. Hillman, T. Gutzler, D. D. Sampson, “Digital Fourier holography enables wide-field, superresolved, microscopic characterization”, in ‘Optics in 2007’, Optics & Photonics News, vol. 18, Dec. 2007, p. 29. S. A. Alexandrov, D. D. Sampson, “Spatial information transmission beyond a system’s diffraction limit using optical spectral encoding of spatial frequency”, J. Opt. A: Pure & Appl. Opt., vol. 10, no. 2, 2008, 025304 (5pp) doi:10.1088/1464-4258/10/2/025304.
