Optical antennas and passive resonant structures, as frequency selective surfaces, configure a new kind of optical
systems that can be classified as belonging to the resonant optics area. Typical antenna-coupled detectors using
microbolometers as transducers have included materials with the largest temperature coefficient of resistance (TCR)
value. These materials are located at the feed point of the antenna where the electric current is the largest and the Joule
effect dissipates the best. At the same time, the signal delivered to the external circuit is also depending on the
resistivity value. This two-material configuration requires al least two e-beam fabrication steps. Although the resistivity
values of metals changes substantially, the actual range of TCR values for most of metals is quite narrow. In this
contribution we analyze how the choice of the material involved in the fabrication of resonant structures may enhance
the bolometric effect. This analysis is made taking into account the electromagnetic interaction of light with the
resonant element. The generated heat changes temperature and this variation produces the signal. Finite element
package Comsol has been used to properly simulate the situation and predict the effect of changing the fabrication to an
unique material, simplifying the manufacturing. Besides, the performance of the structure is depending on the used
material.
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