Could SAFE concept be applied for designing a new synthetic aperture telescope?

Abstract

Synthetic aperture with Fresnel elements (SAFE) is an incoherent holographic imaging system in which the complete hologram is a mosaic of several holograms captured from different points of view. In this paper we investigate a new scheme of SAFE which may be used as a basis for designing a new type of synthetic aperture telescopes. Laboratory in-door experiments may provide the proof of concept for such a new design.

Enhanced-resolution using modified configuration of Fresnel incoherent holographic recorder with synthetic aperture

“…To fulfill this requirement, the distance between the SLM and the camera plane z h should be [14,15] In the next step, the SA is implemented by shifting two SLMs, denoted SLM 1 and SLM 2 , in opposite directions away from the center. Similarly to the T-SAFE [17] method, the two peripheral parts of the spherical wave emitted from the object point are directed by the two SLMs to interfere on the camera plane, enabling an additional sub-hologram to be recorded. However, in this study, contrary to T-SAFE, two converging spherical waves are created by SLM 1 and SLM 2 .…”

“…The improvement of the dual lens SAFE compared to other types of SAFE, including T-SAFE [17], is explored experimentally in this section. The influence of the two modifications, i.e.…”

“…More recently, another scheme of SAFE has been proposed, dubbed telescopic SAFE (T-SAFE) [17]. In T-SAFE, due to a modification of the original SAFE setup, the resolution is improved by the ratio between the synthetic and the physical aperture widths.…”

“…• We propose an SA system in which for every object point, the interference occurs between two closely spaced spherical waves with different curve radii, rather than between spherical and plane waves, as in Refs [16,17]. The system configuration fulfills the requirement of overlap between the two waves on the camera plane, and thus the optimal resolution condition is satisfied.…”

Incoherent digital holography with phase-only spatial light modulators

“…Since its first demonstration, SAFE has evolved in parallel to FINCH, such that every improvement in FINCH has been later adapted to SAFE. [62][63][64] The latest and best performing SAFE configuration, dubbed dual lens SAFE, 64 is reviewed in Sec. 3.1.…”