Strong Purcell Effect for Terahertz Magnetic Dipole Emission with Spoof Plasmonic Structure

Abstract

The magnetic Purcell effect is usually described as a modification of the magnetic dipole emission with a resonator. In an optical spectrum, various metallic and dielectric structures have been proposed to enhance the magnetic dipole emission. However, the enhancement of magnetic dipole emission by a well-designed structure has not been extensively investigated in the terahertz spectrum. Here, we propose a spoof plasmonic structure to enhance strongly the magnetic dipole emission by controlling the electromagnetic environment in the terahertz spectrum. The spoof plasmonic structure with deep-subwavelength scale is designed by periodically inserting metallic strips into a hollow silicon cylinder to obtain the “hot spot” of the localized magnetic field in the structural hollow. The resonant frequency and intensity of the magnetic dipole mode supported in this structure can be tuned freely by tailoring the structural parameters. In this context, we investigate the enhancement of a magnetic dipole emission by putting a magnetic dipole at the hollow of the spoof plasmonic structure. The results indicate that the Purcell factor can be more than 103 for a magnetic dipole emission, which is 1 order of magnitude larger than the hollow bare silicon cylinder case. We furthermore investigate the dependence of the Purcell factor on the structural parameters. The spoof plasmonic structure provides the unique ability to enhance the emission from terahertz magnetic dipoles, opening new avenues for novel magnetic light-matter interactions in the terahertz region.

Fractional‐Order Localized Spoof Surface Plasmons for In‐Phase or Out‐of‐Phase Power Division

“…[18] DOI: 10.1002/adts. 202200645 Many components and devices based on the LSSPs with different functions have been developed, such as sensors, [19][20][21][22][23][24][25] bandpass filters, [26][27] invisibility cloaks, [28][29][30][31] antennas, [32][33][34] vortex-beam emitters, [35][36][37][38][39][40] planar waveguides, [41][42][43] isolators, [44] circulators, [45] directional couplers, [46] and skyrmion generators. [47] According to different classification criteria, they can be divided into one-port, two-port, and four-port components; active and passive devices; [48] reciprocal and nonreciprocal networks; etc.…”

Strongly Coupled Systems for Nonlinear Optics

“…[18] In the weak coupling regime, the spontaneous emission rate can be manipulated readily via tailoring its ambient electromagnetic field, referred to as the Purcell effect. [19,20] This DOI: 10.1002/lpor.202000514 emblematic optical characteristic has been exploited in fertile fields, [21][22][23] including low-threshold laser, [24] single photon source, [25] etc. With augmenting the coupling strength continuously, the rate of energy transfer will overwhelm their attenuation rate, [26] and hence the strongly coupled interaction occurs, featuring the half-light and halfmatter characteristics.…”

Multipolar-sensitive engineering of magnetic dipole spontaneous emission with a dielectric nanoresonator antenna

“…In such a way, a MD mode can be excited in silicon nanospheres and silicon nanodimer from visible to infrared spectrum 20 – 23 . Some other complex structures, including hollow spoof plasmonic structures, constructed of periodically metallic strips in a hollow silicon cylinder, can significantly enhance the quality factor of the magnetic resonance and MD emission 24 , 25 . In the context of light-matter interaction within the near-field, a variety of tapered nanoantennas 26 – 28 and tapered grove nanostructures 29 – 31 demonstrate focusing a strong EM field at the tip side.…”