Directing monolayer tungsten disulfide photoluminescence using a bent-plasmonic nanowire on a mirror cavity

• Published in: The European physical journal. ST, Special topics Special topics, 2022-05, Vol.231 (4), p.807-813
• Main Authors: Chaubey, Shailendra K., Tiwari, Sunny, Shukla, Ashutosh, Gokul, M. A., Rahman, Atikur, Kumar, G. V. Pavan
• Format: Article
• Language: English
• Subjects: Antennas; Atomic; Classical and Continuum Physics; Condensed Matter Physics; Directivity; Emission; Holes; Imaging techniques; Materials Science; Measurement Science and Instrumentation; Molecular; Monolayers; Nanowires; Optical and Plasma Physics; Photoluminescence; Photonic Materials: From Fundamentals to Applications; Physics; Physics and Astronomy; Plasmonics; Regular Article; Silver; Tungsten disulfide
• ISSN: 1951-6355; 1951-6401
• DOI: 10.1140/epjs/s11734-022-00511-y

Designing directional optical antennas without compromising the field enhancement requires specially designed optical cavities. Herein, we report on the experimental observations of directional photoluminescence emission from a monolayer tungsten disulfide using a bent-plasmonic nanowire on a mirror cavity. The geometry provides field enhancement and directivity to photoluminescence by sandwiching the monolayer between an extended cavity formed by dropcasting bent-silver nanowire on a gold mirror. We image the photoluminescence emission wavevectors using Fourier plane imaging technique. The cavity outcouples the emission in a narrow range of wavevectors with a radial and azimuthal spreading of only 11.0 ∘ and 25.1 ∘ , respectively. Furthermore, we performed three-dimensional finite difference time domain-based numerical calculations to corroborate and understand the experimental results. We envisage that the results presented here will be readily harnessed for on-chip coupling applications and in designing inelastic optical antennas.