The previous publications (Miñano et al, 2011) have shown that using a Spherical Geodesic Waveguide (SGW), it can be
achieved the super-resolution up to λ /500 close to a set of discrete frequencies. These frequencies are directly connected
with the well-known Schumann resonance frequencies of spherical symmetric systems. However, the Spherical Geodesic
Waveguide (SGW) has been presented as an ideal system, in which the technological obstacles or manufacturing
feasibility and their influence on final results were not taken into account. In order to prove the concept of superresolution
experimentally, the Spherical Geodesic Waveguide is modified according to the manufacturing requirements
and technological limitations. Each manufacturing process imposes some imperfections which can affect the
experimental results. Here, we analyze the influence of the manufacturing limitations on the super-resolution properties
of the SGW. Beside the theoretical work, herein, there has been presented the experimental results, as well.
Leonhardt demonstrated (2009) that the 2D Maxwell Fish Eye lens (MFE) can focus perfectly 2D Helmholtz waves of
arbitrary frequency, i.e., it can transport perfectly an outward (monopole) 2D Helmholtz wave field, generated by a point source, towards a receptor called “perfect drain” (PD) located at the corresponding MFE image point. The PD has the property of absorbing the complete radiation without radiation or scattering and it has been claimed as necessary to obtain super-resolution (SR) in the MFE. However, a prototype using a “drain” different from the PD has shown λ/5
resolution for microwave frequencies (Ma et al, 2010). Recently, the SR properties of a device equivalent to the MFE,
called the Spherical Geodesic Waveguide (SGW) (Miñano et al, 2012) have been analyzed. The reported results show
resolution up to λ /3000, for the SGW loaded with the perfect drain, and up to λ /500 for the SGW without perfect drain. The perfect drain was realized as a coaxial probe loaded with properly calculated impedance. The SGW provides SR only in a narrow band of frequencies close to the resonance Schumann frequencies. Here we analyze the SGW loaded with a small “perfect drain region” (González et al, 2011). This drain is designed as a region made of a material with complex permittivity. The comparative results show that there is no significant difference in the SR properties for both perfect drain designs.
While multichannel configurations are well established for non-imaging applications, they have not been used yet
for imaging applications. In this paper we present for the first time some of multichannel designs for imaging
systems. The multichannel comprises discontinuous optical sections which are called channels. The phase-space
representation of the bundle of rays going from the object to the image is discontinuous between channels. This
phase-space ray-bundle flow is divided in as many paths as channels there are but it is a single wavefront both at the
source and the target. Typically, these multichannel systems are at least formed by three optical surfaces: two of
them have discontinuities (either in the shape or in the shape derivative) while the last is a smooth one. Optical
surfaces discontinuities cause at the phase space the wave front split in separate paths. The number of discontinuities
is the same in the two first surfaces: Each channel is defined by the smooth surfaces in between discontinuities, so
the surfaces forming each separate channel are all smooth. Aplanatic multichannel designs are also shown and used
to explain the design procedure.
Lately the short-wave infrared (SWIR) has become very important due to the recent appearance on the market of
the small detectors with a large focal plane array. Military applications for SWIR cameras include handheld and
airborne systems with long range detection requirements, but where volume and weight restrictions must be
considered. In this paper we present three different designs of telephoto objectives that have been designed
according to three different methods. Firstly the conventional method where the starting point of the design is an
existing design. Secondly we will face design starting from the design of an aplanatic system. And finally the
simultaneous multiple surfaces (SMS) method, where the starting point is the input wavefronts that we choose.
The designs are compared in terms of optical performance, volume, weight and manufacturability. Because the
objectives have been designed for the SWIR waveband, the color correction has important implications in the
choice of glass that will be discussed in detail.
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