The resolution of a diffraction-limited imaging system is inversely proportional to the aperture size. Instead of using a single large aperture, multiple small apertures are used to synthesize a large aperture. Such a multi-aperture system is modular, typically more reliable and less costly. On the other hand, a multi-aperture system requires phasing sub-apertures to within a fraction of a wave...

The transmission characteristics of wire grid polarizers fabricated in finite apertures are investigated by using a three-dimensional finite-difference time-domain formulation. Specifically, the optical transmissivity and extinction ratio are characterized for a wide variety of geometrical parameters including aperture size in both dimensions, conducting wire fill factor, and polarizer thicknes...

In B-mode imaging, lateral resolution is impeded by the size and shape of the ultrasound beam used to create the image. For improved lateral resolution, a focussing method that utilises a beam model calculated using the Fraunhofer far field approximations to enhance the Synthetic Aperture Focussing Technique (SAFT) is proposed. The Beam Model Weighted Synthetic Aperture Focussing Technique (BMW...

We demonstrate passive large-scale nanophotonic phased arrays in a CMOS-compatible silicon photonic platform. Silicon nitride waveguides are used to allow for higher input power and lower phase variation compared to a silicon-based distribution network. A phased array at an infrared wavelength of 1550 nm is demonstrated with an ultra-large aperture size of 4  mm×4  mm, achieving a record small ...

We study the effect of polarization and aperture geometry on the focal spot size of a high numerical aperture (NA) aplanatic lens. We show that for a clear aperture geometry, illuminating the lens by linear or circular polarization is preferable over radial polarization for spot size reduction applications. For annular aperture and objective lenses of 0.85 NA and above we give the sizes of the ...

underwater target imaging using acoustic waves is possible by employing the method used in synthetic aperture radars. in recent years, synthetic aperture sonar has been the subject of several researches. wherein imaging of underwater moving target is required, inverse synthetic aperture sonar (isas) idea can be used but specifications and limitations of underwater channel should be considered. ...

In the present study, we recorded the kinematics of grasping movements in order to measure the possible interference caused by digits printed on the visible face of the objects to grasp. The aim of this approach was to test the hypothesis that digit magnitude processing shares common mechanisms with object size estimate during grasping. In the first stages of reaching, grip aperture was found t...