57 research outputs found
Optical spectroscopy of novel nanostructures fabricated with a focussed ion beam
No full textDiese Arbeit untersucht mit Methoden der optischen Spektroskopie neuartige photonischen Nanostrukturen die mittels fokussierten Ionenstrahl hergestellt wurden. Unter anderem werden Photolumineszenzmessungen von CdSe/ZnSe Halbleiterquantenpunkten eingebettet in dielektrische Rosonatorsäulen vorgestellt. Außerdem werden ultraschnelle Anrege-Abfrage Experimente an Schlitz-Nut Interferometer in Metall-Ferromagnet Vielschichtsystemen gezeigt.publishe
Optimized higher-order photon state classification by machine learning
No full textThe classification of higher-order photon emission becomes important with more methods being developed for deterministic multiphoton generation. The widely used second-order correlation g(2) is not sufficient to determine the quantum purity of higher photon Fock states. Traditional characterization methods require a large amount of photon detection events, which leads to increased measurement and computation time. Here, we demonstrate a machine learning model based on a 2D Convolutional Neural Network (CNN) for rapid classification of multiphoton Fock states up to |3⟩ with an overall accuracy of 94%. By fitting the g(3) correlation with simulated photon detection events, the model exhibits an efficient performance particularly with sparse correlation data, with 800 co-detection events to achieve an accuracy of 90%. Using the proposed experimental setup, this CNN classifier opens up the possibility for quasi-real-time classification of higher photon states, which holds broad applications in quantum technologies
Electronic readout of optically excited surface plasmons
No full textLeveraging thermal losses as a useful consequence of surface plasmons in metal nanostructures has gained traction in recent years. This thermalization of hot electrons also induces a resistance change to an applied bias current, which we use to realize an all electronic readout of surface plasmons. The interplay of the plasmonic k-vector dependence and the applied bias current allows us to distinguish between linear polarizations of an incident laser beam for polarimetry and polarization imaging uses. This illustrates the potential applications this technique offers as a fully CMOS compatible plasmonic sensor. Moreover, we demonstrate an electronic signal that depends on the delay between two laser pulses on ultrafast timescales, providing insight into the highly non-equilibrium dynamics of the hot electron distribution inside the metal. Using an electronic approach to surface plasmons broadens access and simplifies existing applications, while simultaneously opening the door to new pathways for developing integrated sensors for processes on ultrafast timescales
Using plasmon-induced resistance changes in a tunable metal grating for all-electronic readout
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Testing a discrete model for quantum spin with two sequential Stern-Gerlach detectors and photon Fock states
No full textDespite its unparalleled success, quantum mechanics (QM) is an incomplete
theory of nature. Longstanding concerns regarding its mathematical foundations
and physical interpretation persist, a full century beyond its conception.
Limited by these issues, efforts to move beyond QM have struggled to gain
traction within the broader physics community. One approach to progress in this
direction, which is deeply rooted in the tradition of physics, is the
development of new models for physical systems otherwise treated by QM. One
such model is presented here, which concerns the interaction of a spin system
with sequences of two Stern-Gerlach detectors that may be independently
rotated. Rather than employing the traditional formalism of QM, the proposed
model is supported by tools from discrete mathematics, such as finite groups,
set theory, and combinatorics. Equipped with this novel toolkit, an analog of
Wigner's d-matrix formula is derived and shown to deviate slightly from QM.
With these results, the proposed model is extended to an optical system
involving photon number states passing through a beam splitter. Leveraging
recent advancements in high precision experiments on these systems, we then
propose a means of testing the new model using a tabletop experiment. Hence,
the proposed model not only makes clear testable predictions, but also provides
valuable insight into the essential principles of quantum theory.Comment: 20 pages, 6 figure
Surface enhanced nonlinear optics using lithography-free metasurfaces
No full textWe demonstrate a strong enhancement of second harmonic generation based on a three-layered super absorbing metasurface consisting of an ultrathin spacer layer sandwiched by an array of random metallic nanoparticles and a metal ground plate. (C) 2015 Optical Society of AmericaEICPCI-S(ISTP)[email protected]; [email protected]
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