Unconventional Imaging by Synthetic Apertures

The coherently illumination of a sample by a pinhole generates an interference image (inline-holography). If the pinhole is small (example: diamater 670 nm, lambda = 532 nm) the aperture of the illumination cone is large (NA <= 1) and the spatial resolution will approach 350 nm (Abbelimit). On the other hand the photon flux is very small and limits the detection of the full image area. Larger pinholes (example: diameter 2 µm) reduce the useable aperture of illumination (NA = 0.33) and hence the spatial resolution (about 1000 nm). But the mean photon flux is very increased (in the example by a factor of about 60). The well known dilemma describes the situation: High resolution OR high throughput. By using a pinhole-ARRAY for illumination with larger pinholes (example: 9 pinholes, each 2 µm, distance each 10µm) the low apertures of the coherently illuminated pinholes are overlapping. For an optimised sample position the spatial resolution approach the resolution of the small pinhole (d = 670 nm) and the mean photon flux is increased by the factor of 400. The imaging by synthetic aperture illumination are discussed with a high resolution AND a high throughput.