Near-field mapping of dipole nano-antenna-coupled bolometers
By: Eric Tucker, Jeffrey D' Archangel, Markus Raschke, Edgar Briones, Francisco Javier Gonzalez, Glenn Boreman
Journal of Applied Physics, 114, 033109 (2013)
The near-ﬁeld characteristics of single, double, and arrays of connected dipole nano-antennas coupled to bolometers were studied by infrared scattering scanning near-ﬁeld optical microscopy (s-SNOM) and analyzed by numerical simulations. Results were consistent with classical antenna theory showing the expected pi phase difference across the terminals of the dipoles. However, according to the observed differences between the measurements and simulations, the symmetry of the amplitude signal appeared to be sensitive with respect to the position of the bolometric element relative to the dipoles. The effect of the position of the bolometer on the associated near-ﬁeld distribution suggests an inﬂuence on the coupling and efﬁciency of energy transfer into these detectors, which could be important for determining tolerances in the fabrication of such devices. These results show how near-ﬁeld measurements in general can provide critical information to guide the design of nano-antennas, nano-antenna-phased arrays, and integrated photonic devices.