135 research outputs found
Four-photon scattering in birefringent fibers
Four-photon scattering in nonlinear waveguides is an important physical
process that allows photon-pair generation in well defined guided modes, with
high rate and reasonably low noise. Most of the experiments to date used the
scalar four-photon scattering process in which the pump photons and the
scattered photons have the same polarization. In birefringent waveguides,
vectorial four-photon scattering is also allowed: these vectorial scattering
processes involve photons with different polarizations. In this article, the
theory of four-photon scattering in nonlinear, birefringent, and dispersive
fibers is developed in the framework of the quantum theory of light. The work
focusses on the spectral properties and quantum correlations (including
entanglement) of photon-pairs generated in high-birefringence and
low-birefringence fibers.Comment: 12 pages, 5 figures, submitted to Phys. Rev.
Vector modulation instability induced by vacuum fluctuations in highly birefringent fibers in the anomalous dispersion regime
We report a detailed experimental study of vector modulation instability in
highly birefringent optical fibers in the anomalous dispersion regime. We prove
that the observed instability is mainly induced by vacuum fluctuations. The
detuning of the spectral peaks agrees with linear perturbation analysis. The
exact shape of the spectrum is well reproduced by numerical integration of
stochastic nonlinear Schrodinger equations describing quantum propagation.Comment: 11 pages, 4 figures, to be published in Optics Letter
Progress towards on-chip single photon sources based on colloidal quantum dots in silicon nitride devices
New results on integration of colloidal quantum dots (QDs) into SiN microstructures are reported, including QD positioning with nanometric accuracy and the efficient coupling of their emission to waveguides and cavities. The results are relevant to on-chip quantum optics and information processing
Nearly Blinking-Free, High-Purity Single-Photon Emission by Colloidal InP/ZnSe Quantum Dots
Colloidal core/shell InP/ZnSe quantum dots (QDs), recently produced using an
improved synthesis method, have a great potential in life-science applications
as well as in integrated quantum photonics and quantum information processing
as single-photon emitters. Single-particle spectroscopy of 10-nm QDs with
3.2-nm cores reveals strong photon antibunching attributed to fast (70-ps)
Auger recombination of multiple excitons. The QDs exhibit very good
photostability under strong optical excitation. We demonstrate that the
antibunching is preserved when the QDs are excited above the saturation
intensity of the fundamental-exciton transition. This result paves the way
towards their usage as high-purity on-demand single-photon emitters at room
temperature. Unconventionally, despite the strong Auger blockade mechanism,
InP/ZnSe QDs also display very little luminescence intermittency ("blinking"),
with a simple on/off blinking pattern. The analysis of single-particle
luminescence statistics places these InP/ZnSe QDs in the class of nearly
blinking-free QDs, with emission stability comparable to state-of-the-art
thick-shell and alloyed-interface CdSe/CdS, but with improved single-photon
purity.Comment: 15 pages, 5 figure
Fabrication and characterization of on-chip silicon nitride microdisk integrated with colloidal quantum dots
On-chip hybrid integration of silicon nitride microdisk with colloidal quantum dots
We report on the fabrication of on-chip freestanding silicon nitride microdisks hybridly integrated with embedded colloidal quantum dots. An efficient coupling of quantum dot emission to resonant disk modes in the visible range is demonstrated
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