27 research outputs found
A single-photon transistor using nano-scale surface plasmons
It is well known that light quanta (photons) can interact with each other in
nonlinear media, much like massive particles do, but in practice these
interactions are usually very weak. Here we describe a novel approach to
realize strong nonlinear interactions at the single-photon level. Our method
makes use of recently demonstrated efficient coupling between individual
optical emitters and tightly confined, propagating surface plasmon excitations
on conducting nanowires. We show that this system can act as a nonlinear
two-photon switch for incident photons propagating along the nanowire, which
can be coherently controlled using quantum optical techniques. As a novel
application, we discuss how the interaction can be tailored to create a
single-photon transistor, where the presence or absence of a single incident
photon in a ``gate'' field is sufficient to completely control the propagation
of subsequent ``signal'' photons.Comment: 20 pages, 4 figure
Near-field Electrical Detection of Optical Plasmons and Single Plasmon Sources
Photonic circuits can be much faster than their electronic counterparts, but
they are difficult to miniaturize below the optical wavelength scale. Nanoscale
photonic circuits based on surface plasmon polaritons (SPs) are a promising
solution to this problem because they can localize light below the diffraction
limit. However, there is a general tradeoff between the localization of an SP
and the efficiency with which it can be detected with conventional far-field
optics. Here we describe a new all-electrical SP detection technique based on
the near-field coupling between guided plasmons and a nanowire field-effect
transistor. We use the technique to electrically detect the plasmon emission
from an individual colloidal quantum dot coupled to an SP waveguide. Our
detectors are both nanoscale and highly efficient (0.1 electrons/plasmon), and
a plasmonic gating effect can be used to amplify the signal even higher (up to
50 electrons/plasmon). These results enable new on-chip optical sensing
applications and are a key step towards "dark" optoplasmonic nanocircuits in
which SPs can be generated, manipulated, and detected without involving
far-field radiation.Comment: manuscript followed by supplementary informatio