AAWSAP DIRD, Metamaterials for Aerospace Applications, April 2010

Text

This text came with the file. It may have mistakes. When the text and the image disagree, the image is right.

UNCLASSIFIED/}FOlil OliliiliCililL. W&li QPIL.¥
Far-fiold
.......
m
m
D
m
___....
figure 9. fSL Based on an Indefinite Permittivity Metamaterial Placed Between the Object and the
Image-Releasing Grating. The grating releases into the far field sub-diffraction waves produced by light
scattering off the object. The role of the meta material is to propagate sub-diffraction waves from object to grating.
(Reference 27)
Ever since Merlin's invention (Reference 28) of the sub-diffraction near-field plate, it
has become clear that the interference between sub-diffraction electromagnetic fields
can result in the formation of a deeply sub-wavelength image. The near-field plate,
however, is not an imaging device; its purpose is to create a well-defined image using
an elaborate pre-fabricated sub-wavelength structure on the plate's surface. The goal
for this study is to observe an a priori unknown sub-wavelength image using a near­
field structure. In the past, successes (Reference 19) in retrieving images of sub­
wavelength objects (such as A/20 holes) using an NSOM for radiation detection are
achieved. An NSOM is a near-field instrument, therefore, a much more desirable
detection method would involve far-field detection. To advance this goal, and to
develop a tool sometimes referred to as the FSL, we've initiated research on multi­
beam multi-detector sub-wavelength holography illustrated in Figure 10.
2-nd
k
BeamA/// ~~eamB
figure 10. Tomographic Multi-Beam Multi-Detector Holography of Sub-Wavelength Objects Using
Indefinite Permittivity Medium (IPM). Incident beam(s) scatter off the sub-A object, propagate through the
1PM, and then get re-scattered into the far field by the grating with the period D. The purpose of the multi-detector
arrangement is to disentangle the k1 and kz spatial wave numbers in t he object's spectrum (shown in the left
panel). Beams A and B are phase-shifted with respect to each other.
UNCLASSIFIED/ {EAR OFFICIAk 1!181!!! Bflti
+-+
41t/D
2ro/c
12