We have designed and constructed a custom far-infrared Fourier transform spectrometer using an antenna-coupled bolometer as a detector. The active element of the detector is a superconducting niobium microbridge, and the far-infrared signal is coupled to the microbridge via a planar antenna mounted on a hyperhemispherical silicon lens. The spectrometer uses a broadband blackbody source with fre...

We report on investigations of the interaction of light with nanoscale antennae made from crystalline GaP nanowires (NWs). Using Raman scattering, we have observed strong optical antenna effects which we identify with internal standing wave photon modes of the wire. The antenna effects were probed in individual NWs whose diameters are in the range 40 < d < 300 nm. The data and our calculations ...

It is important to estimate conductivity and permittivity of formation around a borehole. Arrival time and amplitude of the direct wave in single-hole borehole radar is related to the electromagnetic parameters. In this paper, we propose a liner array of dipole antenna elements in a borehole for a receiver. We introduced an optical modulator to transfer the received array signals to optical sig...

High gain broadband plasmonic slot nano-antenna has been considered. The theory of plasmonic slot nano-antenna (PSNA) has been developed. The analytical model takes into account also the electrical field inside the metal due to imperfectness of metal in optical range, as well as numerical investigation based on finite element method (FEM) has been realized. It should be mentioned that Yagi-Uda ...

Bridging the gap between ultrashort pulsed optical waves and terahertz (THz) waves, the THz photoconductive antenna (PCA) is a major constituent for the emission or detection of THz waves by diverse optical and electrical methods. However, THz PCA still lacks employment of advanced breakthrough technologies for high-power THz emission. Here, we report the enhancement of THz emission power by in...

Optical antennas have generated much interest in recent years due to their ability to focus optical energy beyond the diffraction limit, benefiting a broad range of applications such as sensitive photodetection, magnetic storage, and surface-enhanced Raman spectroscopy. To achieve the maximum field enhancement for an optical antenna, parameters such as the antenna dimensions, loading conditions...

We propose and explore theoretically a new concept of ultrafast optical switches based on nonlinear plasmonic nanoantennas. The antenna nanoswitch operates on the transition from the capacitive to conductive coupling regimes between two closely spaced metal nanorods. By filling the antenna gap with amorphous silicon, progressive antenna-gap loading is achieved due to variations in the free-carr...

The electric field enhancement associated with detailed structure within novel optical antenna nanostructures is modeled using the surface integral equation technique in the context of surface-enhanced Raman scattering (SERS). The antennae comprise random arrays of vertically aligned, multiwalled carbon nanotubes dressed with highly granular Ag. Different types of "hot-spot" underpinning the SE...

Nanoscale devices in which the interaction with light can be configured using external control signals hold great interest for next-generation optoelectronic circuits. Materials exhibiting a structural or electronic phase transition offer a large modulation contrast with multi-level optical switching and memory functionalities. In addition, plasmonic nanoantennas can provide an efficient enhanc...

Coupling of a far-field optical mode to electronic states of a quantum absorber or emitter is a crucial process in many applications, including infrared sensors, single molecule spectroscopy, and quantum metrology. In particular, achieving high quantum efficiency for a system with a deep subwavelength quantum absorber/emitter has remained desirable. In this Letter, a hybrid optical antenna base...