Andryieuski, Andrei

Bozhevolnyi, S. I.

Lavrinenko, Andrei

Malureanu, Radu

Radko, I.

Volkov, V. S.

Online Research Database In Technology

                       General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.  • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal   If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.     Downloaded from orbit.dtu.dk on: Dec 18, 2017Efficient and broadband nanoantenna coupler to plasmonic slot waveguideAndryieuski, Andrei; Malureanu, Radu; Lavrinenko, Andrei; Volkov, V. S.; Radko, I.; Bozhevolnyi, S. I.Publication date:2011Link back to DTU OrbitCitation (APA):Andryieuski, A., Malureanu, R., Lavrinenko, A., Volkov, V. S., Radko, I., & Bozhevolnyi, S. I. (2011). Efficient andbroadband nanoantenna coupler to plasmonic slot waveguide. Abstract from International Conference onSurface Plasmon Photonics, Busan, Korea, .Efficient and broadband nanoantenna coupler to plasmonic slot waveguide A. Andryieuski, R. Malureanu, and A. V. Lavrinenko DTU Fotonik, DTU, Ørsteds pl. 343, DK-2800, Kongens Lyngby, Denmark  email: andra@fotonik.dtu.dk  V.S. Volkov, I. Radko and S. I. Bozhevolnyi Institute of Sensors, Signals and Electrotechnics (SENSE), University of Southern Denmark, Niels Bohrs Allé 1, DK-5230 Odense M, Denmark   Plasmonic slot waveguides [1] provide both field confinement and reasonable propagation length. That makes them promising for high-density optical circuits and interconnects [2-3]. However, small size of the slot waveguide mode makes difficult to couple light to it from thick waveguide, e.g., optical fiber. There was proposed by Wen et al. [4] and Huang et al. [5] to use a dipole antenna for this purpose. However, as this is known from the microwave antenna theory [6], just a single dipole antenna does not provide the maximal coupling efficiency (CE) due to low directivity. Moreover, in the works [4-5] the gap of the antenna was made to be the same as the width of the plasmonic waveguide.  In our presentation we show the substantial improvement of the nanoantenna coupler with the broadband coupling efficiency close to maximal possible if one uses tapered connectors between the nanoantenna and waveguide and additional reflectors (see Fig. 1(a)).  The nanocoupler design is presented in Fig. 1(a). It is made from gold and embedded in silica. It consists of the nanoantenna and side and top reflectors. The performance of the nanocoupler is shown in Fig. 1(b), which shows the flow of the Pointing vector from the excitation fiber to the plasmonic waveguide. Simulation and nanocoupler optimization were made in CST Microwave Studio.   Fig. 1: (a) Nanoantenna coupler components: A – plasmonic waveguide, B – nanoantenna, C – side reflector, D – top reflector, E –excitation fiber; (b) nanocoupler in action: power flow from an excitation fiber to the plasmonic waveguide.  Coupling efficiency of the direct fiber-waveguide excitation is below 1% (Fig. 2) at the telecom frequency 193 THz (λ0=1.55 µm). Using the optimized nanoantenna increases CE to 17%. Adding to nanoantenna the side and top reflectors brings efficiency to 35%, which is close to theoretical maximal limit of 50% [6]. Moreover, CE spectrum width at half-maximum is 107 THz that corresponds to relative bandwidth of 51%.    Fig. 2: Coupling efficiency without nanoantenna (triangles), with just nanoantenna (circles) and with nanoantenna, side and top reflectors (stars).  Experimental characterization of the nanocouplers fabricated with electron-beam lithography will be presented at the conference.  [1] L. Liu, Z. Han, and S. He, Opt. Express 13, 6645-6650 (2005).  [2] W.L. Barnes, A. Dereux, and T.W. Ebbesen, Nature 424, 824-830 (2003). [3] D.K. Gramotnev and S.I. Bozhevolnyi, Nat Photon 4, 83-91 (2010).   [4] J. Wen, S. Romanov, and U. Peschel, Optics Express 17, 5925-5932 (2009).  [5] J. Huang, T. Feichtner, P. Biagioni, and B. Hecht,  Nano Letters 9, 1897-1902 (2009).  [6] C.A. Balanis “Antenna Theory: Analysis and Design”, Wiley (2005). 

Efficient and broadband nanoantenna coupler to plasmonic slot waveguide

http://orbit.dtu.dk/ws/files/5587217/Andryieuski.pdf

Efficient and broadband nanoantenna coupler to plasmonic slot waveguide

Abstract

Similar works

Full text

Available Versions

Online Research Database In Technology