856 research outputs found
Local temperature control of photonic crystal devices via micron-scale electrical heaters
We demonstrate a method to locally control the temperature of photonic
crystal devices via micron-scale electrical heaters. The method is used to
control the resonant frequency of InAs quantum dots strongly coupled to GaAs
photonic crystal resonators. This technique enables independent control of
large ensembles of photonic devices located on the same chip at tuning speed as
high as hundreds of kHz
Gallium phosphide photonic crystal nanocavities in the visible
Photonic crystal nanocavities at visible wavelengths are fabricated in a high refractive index (n>3.2) gallium phosphide membrane. The cavities are probed via a cross-polarized reflectivity measurement and show resonances at wavelengths as low as 645 nm at room temperature, with quality factors between 500 and 1700 for modes with volumes 0.7(λ/n)^3. These structures could be employed for submicron scale optoelectronic devices in the visible, and for coupling to emitters with resonances in the visible such as nitrogen vacancy centers, and biomolecules and organic molecules
Theory of Electro-optic Modulation via a Quantum Dot Coupled to a Nano-resonator
In this paper, we analyze the performance of an electro-optic modulator based
on a single quantum dot strongly coupled to a nano-resonator, where electrical
control of the quantum dot frequency is achieved via quantum confined Stark
effect. Using realistic system parameters, we show that modulation speeds of a
few tens of GHz are achievable with this system, while the energy per switching
operation can be as small as 0.5 fJ. In addition, we study the non-linear
distortion, and the effect of pure quantum dot dephasing on the performance of
the modulator.Comment: 9 pages, 7 figure
Generation of nonclassical states of light via photon blockade in optical nanocavities
The generation of nonclassical states of light via photon blockade with time-modulated input is analyzed. We show that improved single-photon statistics can be obtained by adequately choosing the parameters of the driving laser pulses. An alternative method, where the system is driven via a continuous-wave laser and the frequency of the dipole is controlled (e.g., electrically) at very fast time scales is presented
Optimal pulse to generate non-classical photon states via photon blockade
The single photon character of nonclassical states of light that can be generated using photon blockade is analyzed for time domain operation. We show that improved single photon statistics (single photon around 85% with a multi-photon of 8%) can be obtained by adequately choosing the parameters (mainly amplitude and pulse-duration) of the driving laser pulses. An alternative method, where the system is driven via a continuous wave laser and the frequency of the dipole is controlled (e.g. electrically) at very fast timescales is presented. We also show that this non-classical state performs better than a weak coherent pulse, when applied to BB84 quantum cryptography protocol
Coherent probing and saturation of a strongly coupled quantum dot
We coherently probe a quantum dot, strongly coupled to a photonic crystal nano-cavity, using a resonant laser beam. At higher pump power, the coupled systempsilas response becomes highly nonlinear. This coherent probing method has applications for classical and quantum information processing
Single photon nonlinear optics in photonic crystals
We coherently probe a quantum dot that is strongly coupled to a photonic crystal nano-cavity by scattering of a resonant laser beam. The coupled system's response is highly nonlinear as the quantum dot saturates with nearly one photon per cavity lifetime. This system enables large amplitude and phase shifts of a signal beam via a control beam, both at single photon levels. We demonstrate photon-photon interactions with short pulses in a system that is promising for ultra-low power switches and two-qubit quantum gates
Dielectric Metasurfaces for Complete Control of Phase and Polarization with Subwavelength Spatial Resolution and High Transmission
Metasurfaces are planar structures that locally modify the polarization,
phase, and amplitude of light in reflection or transmission, thus enabling
lithographically patterned flat optical components with functionalities
controlled by design. Transmissive metasurfaces are especially important, as
most optical systems used in practice operate in transmission. Several types of
transmissive metasurfaces have been realized, but with either low transmission
efficiencies or limited control over polarization and phase. Here we show a
metasurface platform based on high-contrast dielectric elliptical nano-posts
which provides complete control of polarization and phase with sub-wavelength
spatial resolution and experimentally measured efficiency ranging from 72% to
97%, depending on the exact design. Such complete control enables the
realization of most free-space transmissive optical elements such as lenses,
phase-plates, wave-plates, polarizers, beam-splitters, as well as polarization
switchable phase holograms and arbitrary vector beam generators using the same
metamaterial platform.Comment: Nature Nanotechnology (2015
Engineering anti-bunching via photon blockade in photonic crystal cavity-quantum dot systems
Methods to improve single photon generation via photon-blockade in a photonic-crystal cavity with a strongly coupled quantum-dot are presented. With realistic system parameters, significant improvement in second-order-auto-correlation g^2 (0) (from 0.93 to 0.79) is achieved
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