6 research outputs found
Proposed Coupling of an Electron Spin in a Semiconductor Quantum Dot to a Nanosize Optical Cavity
We propose a scheme to efficiently couple a single quantum dot electron spin
to an optical nano-cavity, which enables us to simultaneously benefit from a
cavity as an efficient photonic interface, as well as to perform high fidelity
(nearly 100%) spin initialization and manipulation achievable in bulk
semiconductors. Moreover, the presence of the cavity speeds up the spin
initialization process beyond GHz.Comment: 6 figure
Single-Cell Photonic Nanocavity Probes
In this report, we demonstrate for the first time photonic
nanocavities
operating inside single biological cells. Here we develop a nanobeam
photonic crystal (PC) cavity as an advanced cellular nanoprobe, active
in nature, and configurable to provide a multitude of actions for
both intracellular sensing and control. Our semiconductor nanocavity
probes emit photoluminescence (PL) from embedded quantum dots (QD)
and sustain high quality resonant photonic modes inside cells. The
probes are shown to be minimally cytotoxic to cells from viability
studies, and the beams can be loaded in cells and tracked for days
at a time, with cells undergoing regular division with the beams.
We present in vitro label-free protein sensing with our probes to
detect streptavidin as a path towards real-time biomarker and biomolecule
detection inside single cells. The results of this work will enable
new areas of research merging the strengths of photonic nanocavities
with fundamental cell biology
Single-Cell Photonic Nanocavity Probes
In this report, we demonstrate for the first time photonic
nanocavities
operating inside single biological cells. Here we develop a nanobeam
photonic crystal (PC) cavity as an advanced cellular nanoprobe, active
in nature, and configurable to provide a multitude of actions for
both intracellular sensing and control. Our semiconductor nanocavity
probes emit photoluminescence (PL) from embedded quantum dots (QD)
and sustain high quality resonant photonic modes inside cells. The
probes are shown to be minimally cytotoxic to cells from viability
studies, and the beams can be loaded in cells and tracked for days
at a time, with cells undergoing regular division with the beams.
We present in vitro label-free protein sensing with our probes to
detect streptavidin as a path towards real-time biomarker and biomolecule
detection inside single cells. The results of this work will enable
new areas of research merging the strengths of photonic nanocavities
with fundamental cell biology
Inverse Design of Optical Vortex Beam Emitters
Vortex
beams are stable solutions of Maxwell’s equations
that carry phase singularities and orbital angular momentum, unique
properties that give rise to many applications in the basic sciences,
optical communications, and quantum technologies. Scalable integration
and fabrication of vortex beam emitters will allow these applications
to flourish and enable new applications that are not possible with
traditional optics. Here we present a general framework to generate
integrated vortex beam emitters using photonic inverse design. We
experimentally demonstrate the generation of vortex beams with angular
momentum spanning −3ℏ to 3ℏ. We show the generality of this design procedure by designing a
vortex beam multiplexer capable of exciting a custom vortex beam fiber.
Finally, we produce foundry-fabricated beam emitters with wide bandwidths
and high efficiencies that take advantage of multilayer heterogeneous
integration
Second-Harmonic Generation in GaAs Photonic Crystal Cavities in (111)B and (001) Crystal Orientations
We
demonstrate second-harmonic generation in photonic crystal cavities
in (001)- and (111)B-oriented GaAs. The fundamental resonance is at
1800 nm, leading to generated second harmonic below the GaAs band
gap. Below-band-gap operation minimizes absorption of the second-harmonic
and two-photon absorption of the pump. Photonic crystal cavities were
fabricated in both orientations at various in-plane rotations of the
GaAs substrate. The rotation dependence and far-field patterns of
the second harmonic match simulation. We observe similar maximum efficiencies
of 1.2%/W in (001)- and (111)B-oriented GaAs
Direct Bandgap Light Emission from Strained Germanium Nanowires Coupled with High‑Q Nanophotonic Cavities
A silicon-compatible light source
is the final missing piece for completing high-speed, low-power on-chip
optical interconnects. In this paper, we present a germanium nanowire
light emitter that encompasses all the aspects of potential low-threshold
lasers: highly strained germanium gain medium, strain-induced pseudoheterostructure,
and high-Q nanophotonic cavity. Our nanowire structure presents greatly
enhanced photoluminescence into cavity modes with measured quality
factors of up to 2000. By varying the dimensions of the germanium
nanowire, we tune the emission wavelength over more than 400 nm with
a single lithography step. We find reduced optical loss in optical
cavities formed with germanium under high (>2.3%) tensile strain.
Our compact, high-strain cavities open up new possibilities for low-threshold
germanium-based lasers for on-chip optical interconnects