design-fabrication-experimental-characterization-plasmonic

Design, Fabrication, and Experimental Characterization of Plasmonic Photoconductive Terahertz Emitters

In this video article we present a detailed demonstration of a highly efficient method for generating terahertz waves. Our technique is based on ...

University of Michigan 

We analyze the interaction of electromagnetic waves with double-layered subwavelength metallic slits on a dielectric substrate. This structure allows efficient transmission of an incident TM-polarized electromagnetic wave into the dielectric substrate, due to the presence of surface modes which couple the incident wave to the TEM waveguide modes supported by the subwavelength metallic slits. Our study shows that electromagnetic transmission through double-layered subwavelength metallic slits is strongly geometry dependent. Based on this observation, a terahertz modulation scheme is presented which, compared to existing terahertz modulator solutions, has the promise of significant enhancement in modulation index over a broad range of terahertz frequencies.

Design of reconfigurable metallic slits for terahertz beam modulation.

Nous analysons l&#39;interaction des ondes &eacute;lectromagn&eacute;tiques avec fentes m&eacute;talliques sous-longueurs double couche sur un substrat di&eacute;lectrique. Cette structure permet une transmission efficace d&#39;une onde incidente d&#39;&eacute;lectromagn&eacute;tique polaris&eacute;e TM dans le substrat di&eacute;lectrique, en raison de la pr&eacute;sence de modes de surfaces qui couple l&#39;incident des vagues pour les modes de guide d&#39;onde TEM soutenus par les fentes m&eacute;talliques sous-longueurs. Notre &eacute;tude montre que la transmission &eacute;lectromagn&eacute;tique par fentes m&eacute;talliques sous-longueurs double couche est fortement d&eacute;pendante de la g&eacute;om&eacute;trie. Bas&eacute; sur cette observation, un syst&egrave;me de modulation t&eacute;rahertz est pr&eacute;sent&eacute; qui, par rapport aux solutions existantes de modulateur t&eacute;rahertz, a la promesse d&#39;une am&eacute;lioration significative de l&#39;indice de modulation sur une large gamme de fr&eacute;quences t&eacute;rahertz.

Conception des reconfigurables fentes m&eacute;talliques pour la modulation de faisceau t&eacute;rahertz.

Analizziamo l&#39;interazione delle onde elettromagnetiche con feritoie metallico subwavelength a doppio strato su un substrato dielettrico. Questa struttura consente la trasmissione efficiente di un&#39;onda incidente elettromagnetico polarizzato TM nel substrato dielettrico, dovuto alla presenza di modalit&agrave; superficiale quale coppia onda incidente alle modalit&agrave; di guida d&#39;onda TEM supportata da fessure metallico subwavelength. Il nostro studio indica che la trasmissione elettromagnetica attraverso fessure metallici a doppio strato subwavelength &egrave; fortemente dipendente dalla geometria. Basato su questa osservazione, uno schema di modulazione terahertz &egrave; presentato che, rispetto alle soluzioni esistenti di modulatore terahertz, &egrave; la promessa di miglioramento significativo nell&#39;indice di modulazione sopra una vasta gamma di frequenze terahertz.

Disegno delle feritoie metallici riconfigurabile per la modulazione del fascio terahertz.

We experimentally demonstrate continuous-wave ultraviolet emission through forth-harmonic generation in a millimeter-scale lithium niobate whispering-gallery resonator pumped with a telecommunication-compatible infrared source. The whispering-gallery resonator provides four spectral lines at ultraviolet, visible, near-infrared and infrared, which are equally spaced in frequency via the cascaded-harmonic process and span a 2-octave frequency band. Our technique relies on a variable crystal poling and high transverse order of the modes for phase-matching and a resonator quality factor of over 10(7) to allow cascaded-harmonic generation up to the fourth-harmonic at input pump powers as low as 200 mW. The compact size of the whispering gallery resonator pumped at telecommunication-compatible infrared wavelengths and the low pump power requirement make our device a promising ultraviolet light source for information storage, microscopy, and chemical analysis.

Continuous-wave ultraviolet emission through fourth-harmonic generation in a whispering-gallery resonator.

Nous d&eacute;montrons exp&eacute;rimentalement onde continue &eacute;mission ultraviolette par g&eacute;n&eacute;ration de suite harmonique dans un r&eacute;sonateur de chuchoter-Galerie &eacute;chelle millim&eacute;trique au lithium niobate pomp&eacute; avec une source infrarouge de t&eacute;l&eacute;communication compatibles. Le r&eacute;sonateur de whispering-gallery fournit quatre raies spectrales &agrave; ultraviolet, visible, proche infrarouge et infrarouge, qui sont espac&eacute;s de fa&ccedil;on &eacute;gale en fr&eacute;quence via le processus de mise en cascade de r&eacute;gime-harmonique et couvrent une bande de fr&eacute;quences de 2 octaves. Notre technique se fonde sur une variable crystal perchage et ordre transversal sup&eacute;rieur des modes de couplage de phase et un facteur de qualit&eacute; du r&eacute;sonateur de sur 10 (7) pour permettre la g&eacute;n&eacute;ration harmonique en cascade jusqu&#39;&agrave; la quatri&egrave;me harmonique &agrave; puissances d&#39;entr&eacute;e pompe aussi bas que 200 mW. La taille compacte du r&eacute;sonateur Galerie murmure pomp&eacute; aux longueurs d&#39;onde infrarouges compatible telecommunication et le besoin de puissance de pompe faible font notre appareil une source de lumi&egrave;re ultraviolette prometteuse pour le stockage de l&#39;information, la microscopie et analyse chimique.

Onde continue &eacute;mission ultraviolette par g&eacute;n&eacute;ration de quatri&egrave;me harmonique dans un r&eacute;sonateur de la Galerie des chuchotements.

Noi dimostrare sperimentalmente un emissione ultravioletta attraverso via-harmonic generation in un risonatore di sussurrando-Galleria di scala millimetrata litio niobato pompato con una sorgente a raggi infrarossi telecomunicazioni-compatibile. Il risonatore sussurrando-Galleria fornisce quattro linee spettrali in ultravioletto, visibile, vicino infrarosso e infrarosso, che sono equidistanti in frequenza tramite il processo a cascata-armonica e abbracciano una banda di frequenza 2-ottava. La nostra tecnica si basa su un cristallo variabile poling e alto ordine trasversale delle modalit&agrave; per la fase di corrispondenza e un fattore di qualit&agrave; del risonatore di oltre 10 per consentire la generazione armonica a cascata fino alla quarta armonica a potenze di ingresso pompa basso quanto 200 mW. Le dimensioni compatte del risonatore whispering gallery pompato a lunghezze d&#39;onda infrarosse di telecomunicazione-compatibile e il requisito di alimentazione pompa bassa rendono il nostro dispositivo una sorgente di luce ultravioletta promettente per la memorizzazione di informazioni, microscopia e analisi chimica.

Mona Jarrahi

Electrical Engineering and Computer Science Department

University of Michigan

Design, Fabrication, and Experimental Characterization of Plasmonic Photoconductive Terahertz Emitters

Mona Jarrahi

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Electrical Engineering and Computer Science Department

University of Michigan

Design, Fabrication, and Experimental Characterization of Plasmonic Photoconductive Terahertz Emitters

Electrical Engineering and Computer Science Department