2016/06/16 by Denis G. Baranov, Sergey V. Makarov, Baranov, Denis G. +6
Engineering · Physics and Astronomy · #FOS: Physical sciences #Optics (physics.optics) #Photonic Crystals and Applications #Photonic and Optical Devices #Plasmonic and Surface Plasmon Research
paper · pdf · doi:10.48550/arxiv.1606.05199
openalex publication_date 2016/06/16 · openalex created_date 2022/10/03 · openalex updated_date 2026/07/28
Achievement of all-optical ultrafast signal modulation and routing by a\nlow-loss nanodevice is a crucial step towards an ultracompact optical chip with\nhigh performance. Here, we propose a specifically designed silicon dimer\nnanoantenna, which is tunable via photoexcitation of dense electron-hole plasma\nwith ultrafast relaxation rate. Basing on this concept, we demonstrate the\neffect of beam steering up to 20 degrees via simple variation of incident\nintensity, being suitable for ultrafast light routing in an optical chip. The\neffect is demonstrated both in the visible and near-IR spectral regions for\nsilicon and germanium based nanoantennas. We also reveal the effect of\nelectron-hole plasma photoexcitation on local density of states (LDOS) in the\ndimer gap and find that the orientation averaged LDOS can be altered by 50 %,\nwhereas modification of the projected LDOS can be even more dramatic: almost\n500 % for transverse dipole orientation. Moreover, our analytical model sheds\nlight on transient dynamics of the studied nonlinear nanoantennas, yielding all\ntemporal characteristics of the proposed ultrafast nanodevice. The proposed\nconcept paves the ways to creation of low-loss, ultrafast, and compact devices\nfor optical signal modulation and routing.\n