![]() An effective aperture of 0.72 mm with lower cost is realized by utilizing less than 1/2 processing area. The proposed UOSA metalens consists of three identical and concentric annular sectors sub‐aperture metalens based on a gallium nitride nanobrick array, which can effectively focus the unpolarized visible light into the same point. Herein, an unconventional optical sparse‐aperture (UOSA) metalens is developed with a Wiener filtering algorithm to obtain a high‐quality image. However, the realization of a large‐aperture metalens, which is composed of billions of nanoscale building blocks, poses significant challenges for both process technology and manufacturing cost. Such imaging systems are suitable only for the astronomical application.Ī flat and compact metasurface‐based optical metalens with superior performance can be widely used for focusing and imaging. This suggests that the extremely high image resolution can be achieved in the interferometric imaging systems, but it generally has a very small field of view. Also the computer simulation results are presented and match the theoretical results very well. At the good approximation, the FOV is about one-sixth of an Airy disk of an elementary aperture diffraction. Based on this condition, the angle of field-of-view (FOV) in the object space is analyzed and determined. The approximate condition, which should be followed by optical aperture synthesis imaging interferometry, is obtained by comparing two models. In this paper, by using the generalized imaging theory of a diffraction-limited incoherent imaging system, the pinhole model and the circular aperture model of the interferometry are presented and derived. Both the amplitude and phase of the visibility are needed to produce images of a complex object structure by Fourier inversion. Interferometric imaging systems measure the complex visibility, which is the Fourier transform of the source brightness distribution, according to the van Cittert-Zernike theorem. We present a design solution that meets the requirements for the best possible exploitation of the time-delay integration mode over a field of view of 0.7 degrees x 0.7 degrees. Optical aberrations, particularly distortion and coma, play a crucial role in the efficiency of this technique. In this framework, data acquisition is performed by an array of CCDs working in time-delay integration mode. We assume a mission profile similar to that of the Global Astrometric Interferometer for Astrophysics mission of the European Space Agency. Our work focuses on the geometric optimization and minimization of aberration of such an astrometric interferometer, which is able to observe astronomical targets down to the visual magnitude (mag) mv = 20 mag, with an accuracy in the measurements of 10 micro-arcseconds at mv = 15 mag. We discuss the design and the performance of a Fizeau interferometer with a long focal length and a large field of view that is well suited for a global astrometry space mission.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |