posted on 2020-03-10, 20:45authored byLu Ding, Dmitry Morits, Reuben Bakker, Shiqiang Li, Damien Eschimese, Shiyang Zhu, Ye Feng Yu, Ramon Paniagua-Dominguez, Arseniy I. Kuznetsov
Dielectric nanoantennas represent
a new branch of nanophotonics
that allows efficient control of light scattering at nanoscale. Coupled
nanoantennas can guide light on a chip over large distances without
radiation losses, enabling a new nanoantenna-based silicon photonics
platform with enchanced functionalities for light-on-chip integration.
Here, an all-optical on-chip modulator based on a one-dimensional
chain of silicon nanoantennas is proposed and experimentally demonstrated
in the 1.55 μm telecommunication wavelength range. A resonator,
with a quality factor up to 104, is designed on the basis
of a chain of coupled silicon nanoantennas, each supporting the electric
dipole Mie resonance. Wafer-level fabrication of the nanoantennas
is realized using CMOS compatible photolithography. High-speed modulation
of the cavity mode is experimentally demonstrated via optical injection
of free electrons and holes using a pulsed laser. The modulator is
shown to have a response time of 50 ps and modulation depth beyond
25 dB, with 10 dB switching power being as low as ∼50 fJ. Low
power and high-speed switching of the proposed device combined with
the large-scale fabrication capabilities pave the way to applications
of this dielectric nanoantenna-based approach to industrial on-chip
photonics.