Sub-wavelength probing and modification of photonic crystal nano-cavities
Year: 2010
Authors: Vignolini S., Intonti F., Riboli F., Zani M., Vinattieri A., Wiersma D., Colocci M., Balet L., Li LH., Francardi M., Gerardino A., Fiore A., Gurioli M.
Autors Affiliation: Univ Florence, LENS, I-50019 Sesto Fiorentino, Italy; Univ Florence, Dept Phys, I-50019 Sesto Fiorentino, Italy; CNISM, Unita Ric Firenze, I-50019 Sesto Fiorentino, Italy; Ecole Polytech Fed Lausanne, Inst Photon & Quantum Elect, Stn 3, CH-1015 Lausanne, Switzerland; CNR, Inst Photon & Nanotechnol, I-00156 Rome, Italy; Eindhoven Univ Technol, COBRA Res Inst, NL-5600 MB Eindhoven, Netherlands
Abstract: In this work we present a sizeable and reversible spectral tuning of the resonances of a two-dimensional photonic crystal nanocavity by exploiting the introduction of a sub-wavelength size glass tip. The comparison between experimental near-field data and results of numerical calculations shows that the spectral shift induced by the tip is proportional to the local electric field intensity of the cavity mode. This observation proves that the electromagnetic local density of states in a microcavity can be directly measured by mapping the tip-induced spectral shift with a scanning near-field optical microscope. Moreover, a non-linear control on the cavity resonance is obtained by exploiting the local heating induced by near-field laser excitation at different excitation powers. The temperature gradient due to the optical absorption results in an index of refraction gradient which modifies the dielectric surroundings of the cavity and shifts the optical modes. (C) 2009 Elsevier B.V. All rights reserved.
Journal/Review: PHOTONICS AND NANOSTRUCTURES-FUNDAMENTALS AND APPLICATIONS
Volume: 8 (2) Pages from: 78 to: 85
KeyWords: Photonic crystals; Near-field; TuningDOI: 10.1016/j.photonics.2009.08.004Connecting to view paper tab on IsiWeb: Click here