arXiv subjects

C. M. Hooper

Publications and source records attributed to C. M. Hooper.

2 recordsLinked to original sources

arXiv2026

Switchable selective backscatter modulation via the Kerker effect

We design a reflective scatterer that operates only in the backscatter direction using modulation of the Kerker effect. This being a phenomena where the resonant modes of a scattering object produce total destructive interference in the backscatter direction. Our design consists of a dielectric shell and an interior metal element that provide the required dipolar contributions for Kerker interference with angular stability. By incorporating a PIN diode, we obtain a scatterer that exhibits strong amplitude modulation in the backscattering direction that is weaker at other bistatic angles. Backscatter modulation is a key technology to connect everyday objects but can be vulnerable to eavesdropping, the device presented in this work may help guard against such flaws.

physics.app-ph↗

arXiv2025

Effects due to generation of negative frequencies during temporal diffraction

Temporal diffraction from rapidly time-modulated materials can generate new frequency components not present in an incident wave. In such an experiment, the spectral extent of these new frequencies is determined by the rate of modulation relative to the period of the oscillating field. Here we present a temporal diffraction experiment carried out in the far-infrared (THz) spectral region. Using graphene, a fast modulator for this spectral domain, we show that one can modulate the transmission significantly faster than the period of a narrow band THz field. This leads to a large bandwidth for the generated frequencies, including the generation of negative frequency components. We show that interference between negative and positive frequency components give rise to distinctive oscillatory features in the transmitted spectrum.

physics.optics↗