{"id":184,"date":"2019-07-05T15:30:12","date_gmt":"2019-07-05T19:30:12","guid":{"rendered":"https:\/\/sites.bu.edu\/biomicroscopy\/?page_id=184"},"modified":"2019-07-15T09:42:54","modified_gmt":"2019-07-15T13:42:54","slug":"paw","status":"publish","type":"page","link":"https:\/\/sites.bu.edu\/biomicroscopy\/research\/paw\/","title":{"rendered":"Partitioned aperture wavefront imaging"},"content":{"rendered":"

\"\"A wavefront imager provides images of the phase and amplitude of a wavefront. Several techniques for wavefront imaging have been developed. Most of these involve the use of a laser, and are thus susceptible to speckle noise. Techniques that do not require a laser generally require collimated light, meaning they are not light efficient, or require moving parts and the acquisition of multiple images, meaning they are slow. We have recently developed a wavefront imager that is fast (single shot), achromatic (works with broadband light), light efficient (works with extended sources), and simple. The technique is based on partitioning the detection aperture of a standard microscope into four quadrants with the use of four off-axis lens. These lenses provide four oblique detection images that are simultaneously acquired with a single camera. The data provided by these four images enables the reconstruction of wavefront phase and amplitude with a simple numerical algorithm that runs in real time (video rate).<\/p>\n

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17. Surface topography of 4 pixels of a deformable mirror\/ Topography calculated based on phase-gradient images acquired by a PAW microscope in reflection mode. Image acquisition was video rate. Topography precision is about 3nm.<\/figcaption><\/figure>\n
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Reconstructed phase image based on phase-gradient images acquired by trans-illumination PAW microscope.<\/figcaption><\/figure>\n

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