Informal Seminar DQMP – Dr. Achim Woessner (ICFO – Barcelona) – Flatland nano-optics with graphene plasmons

Date/Time
Date(s) - 15/06/2017
11h00 - 12h00


MaNEP Room – Ecole de Physique

 

Abstract:

Plasmons are charge oscillations coupled to electromagnetic radiation. In graphene plasmons can be confined to extreme subwavelength scales while still having a long lifetime and their wavelength is tunable in situ. Graphene plasmonics is a relatively new research area but has already attracted a lot of attention. This is undoubtedly due to the fact that graphene plasmons are extremely versatile. They are a unique platform for exploring the limits of light matter interaction, two dimensional transformation optics, biosensing, and mid-infrared integrated optics. [1,2] In this seminar I will show how graphene plasmons can be studied using scattering-type scanning near-field optical microscopy (s-SNOM) as well as a technique based on s-SNOM we developed called near-field photocurrent nanoscopy. I will introduce an experiment where we explore the limitations of the graphene plasmon lifetime at room temperature. [3] I will then show an optical phase modulator which is capable of tuning the phase in situ from 0 to 2pi with a footprint of only 350nm. [4] Finally I will introduce a new measurement technique called infrared photocurrent nanoscopy and show how it can be used to detect graphene plasmons electrically from the infrared to the terahertz. [5,6,7]

 

[1] D.N. Basov et al., Science  354, aag1992 (2016) [2] T. Low et al., Nature Materials 16, 182-194 (2017) [3] A. Woessner, M.B. Lundeberg, Y. Gao et al., Nature Materials 14, 421-425 (2015) [4] A. Woessner, Y. Gao et al., accepted in Nature Photonics (2017) [5] A. Woessner et al., Nature Communications 7, 10783 (2016) [6] M.B. Lundeberg et al., Nature Materials 16, 204-207 (2017) [7] P. Alonso-Gonzalez et al., Nature Nanotechnology 12, 31-35 (2017)

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