Continuously-tunable Cherenkov-radiation-based detectors via plasmon index control

Abstract

A recent study [PRB 100, 075427 (2019)], finally, demonstrated the plasmon-analog of refractive index enhancement in metal nanostructures (MNSs), which has already been studied in atomic clouds for several decades. Here, we simply utilize this phenomenon for achieving continuously-tunable enhanced Cherenkov radiation (CR) in MNSs. Beyond enabling CR from slow-moving particles, or increasing its intensity, the phenomenon can be used in continuous-tuning of the velocity cutoff of particles contributing to CR. More influentially, this allows a continuously-tunable analysis of the contributing particles as if the data is collected from many different detectors, which enables data correction. The phenomenon can also be integrated into lattice MNSs, for continuous medium tuning, where a high density of photonic states is present and the threshold for the CR can even be lifted. Additionally, vanishing absorption can heal radiation angle distortion effects caused by the metallic absorption.

Fano enhancement of second harmonic field via dark-bright plasmon coupling

“…Enhancement, due to path interference effects, of both linear [22] and nonlinear [23] phenomena that emerged from the hot spots of plasmonic structures, is well studied via coupling plasmonic modes to the two-level quantum structures. These path interference effects (Fano resonances), besides the emitter-plasmon coupling, can also appear when the plasmon mode of the metal nanoparticle is coupled to a long-live dark plasmon mode [24].…”

All-optical switching via coherent control of plasmon resonances

“…Recently, plasmonic analogue of a well-known effect in quantum optics named as enhancement of index of refraction (EIR) [25] is theoretically reported in coupled plasmonic resonators, enabling the maximum susceptibility (strong electromagnetic response) with zero optical losses at resonance frequencies via coherent control of surface plasmons [26]. Thus, apart form some newly proposed potential applications [27,28], this approach has suggested a unique path to realize loss-compensated plasmonic devices operating at resonance frequencies through extraordinary enhancement of refractive index without using any gain media [29][30][31][32] and nonlinear processes [23,33].…”

Ultra-large actively tunable photonic band gaps via plasmon-analog of index enhancement

“…Plasmon index enhancement has been exploited in Ref. [44] for achieving a continuously-tunable Cherenkov-radiation-based particle detector, ignoring the periodicity effects.…”

“…can be obtained [35,44]. The dimensionless oscillator strength f is determined by setting nonenhanced susceptibility χ(ω = ω 0 , g = 0) = f /(γ 1 /ω 0 ) [44] to P 1 /E 1 , with P 1 is the polarization density calculated for ellipsoid nanorods [35,44,45], for 1 dimer in index-enhanced layer (10 nm), with volume V layer =10×100×100 nm 3 in Fig. 1.…”

“…This limitation, actually, occurs due to two transient times. The decay time of the surface plasmon oscillations on silver, used in this work [35,44], is already about 40 fs. The switch time is also determined by the relaxation time, appearing due to the interaction between the two nanorods 5 .…”