Sebastian Franke

ORCID: 0000-0002-4233-9251
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About
Contact & Profiles
Research Areas
  • Photonic and Optical Devices
  • Mechanical and Optical Resonators
  • Plasmonic and Surface Plasmon Research
  • Quantum Information and Cryptography
  • Quantum optics and atomic interactions
  • Semiconductor materials and devices
  • Orbital Angular Momentum in Optics
  • Advanced Fiber Laser Technologies
  • Nonlinear Photonic Systems
  • Organic Light-Emitting Diodes Research
  • Photonic Crystals and Applications
  • Quantum Mechanics and Non-Hermitian Physics
  • Photorefractive and Nonlinear Optics
  • Laser-Matter Interactions and Applications
  • Electronic and Structural Properties of Oxides
  • Topological Materials and Phenomena
  • Atomic and Subatomic Physics Research
  • Terahertz technology and applications
  • Optical Network Technologies
  • Thin-Film Transistor Technologies
  • Strong Light-Matter Interactions
  • Semiconductor Lasers and Optical Devices
  • Advanced Photonic Communication Systems
  • Optical Coatings and Gratings
  • Metamaterials and Metasurfaces Applications

Queen's University
2021-2024

Technische Universität Berlin
2019-2024

Technische Universität Braunschweig
2016-2017

Fraunhofer Institute for Photonic Microsystems
2008-2012

We introduce a second quantization scheme based on quasinormal modes, which are the dissipative modes of leaky optical cavities and plasmonic resonators with complex eigenfrequencies. The theory enables construction multi-plasmon/photon Fock states for arbitrary three-dimensional gives solid understanding to limits phenomenological Jaynes-Cummings models. In general case, we show how different interfere through an off-diagonal mode coupling demonstrate these results affect cavity-modified...

10.1103/physrevlett.122.213901 article EN Physical Review Letters 2019-05-29

We employ a recently developed quantization scheme for quasinormal modes (QNMs) to study nonperturbative open cavity-QED system consisting of hybrid metal-dielectric resonator coupled quantum emitter. This cavity allows one explore the complex coupling between low $Q$ (quality factor) resonance and high resonance, manifesting in striking Fano an effect that is not captured by traditional schemes using normal or Jaynes-Cummings (JC) type model. The QNM approach rigorously includes dissipative...

10.1103/physrevresearch.2.033456 article EN cc-by Physical Review Research 2020-09-21

We demonstrate a fundamental breakdown of the photonic spontaneous emission (SE) formula derived from Fermi's golden rule, in absorptive and amplifying media, where one assumes SE rate scales with local photon density states, an approach often used more complex, semiclassical nanophotonics simulations. Using rigorous quantization macroscopic Maxwell equations presence arbitrary linear we derive corrected rule master equation for quantum two-level system (TLS) that yields pumping term...

10.1103/physrevlett.127.013602 article EN Physical Review Letters 2021-06-29

The authors derive a correction to the spontaneous emission rate and classical Purcell factor in linear media that includes gain loss within framework of light-matter theory. results fully recover recently presented quantum mechanical form, establishing an essential classical-to-quantum correspondence emission, are extended also account for local field effects.

10.1103/physreva.109.013513 article EN Physical review. A/Physical review, A 2024-01-23

We first present a quasinormal mode (QNM) theory for coupled loss-gain resonators working near an exceptional point. Assuming linear media, which can be fully quantified using the complex pole properties of QNMs, we show how QNMs yield quantitatively good model to full dipole spontaneous emission response in Maxwell's equations at various spatial positions and frequencies (linear response). also develop highly accurate intuitive QNM coupled-mode theory, used rigorously such systems only bare...

10.1103/physrevx.11.041020 article EN cc-by Physical Review X 2021-10-28

The loss of gauge invariance in models light-matter interaction which arises from material and photonic space truncation can pose significant challenges to conventional quantum optical when matter light strongly hybridize. In structured environments, necessary practice achieve strong coupling, a rigorous model field quantization within the medium is also needed. Here we use framework macroscopic QED by quantizing fields an arbitrary system, with spatially dependent dispersive absorptive...

10.1103/physreva.107.013722 article EN Physical review. A/Physical review, A 2023-01-27

Quantum emitters coupled to plasmonic resonators are known allow enhanced broadband Purcell factors, and such systems have been recently suggested as possible candidates for on-demand single photon sources, with fast operation speeds. However, a true source has strict requirements of high efficiency (brightness) quantum indistinguishability the emitted photons, which can be quantified through two-photon interference experiments. To help address this problem, we employ extend developed...

10.1021/acsphotonics.9b00849 article EN ACS Photonics 2019-07-08

We describe an efficient near-field to far-field transformation for optical quasinormal modes, which are the dissipative modes of open cavities and plasmonic resonators with complex eigenfrequencies. As application theory, we show how one can compute reservoir (or regularized modes) outside resonator, essential use in both classical quantum optics. subsequently demonstrate efficiently parameters necessary theory quantized [Franke et al., Phys. Rev. Lett. 122, 213901 (2019)]. To confirm...

10.1103/physrevb.101.205402 article EN Physical review. B./Physical review. B 2020-05-01

In the presence of arbitrary three-dimensional linear media with material loss and amplification, we present an electromagnetic field quantization scheme for quasinormal modes (QNMs), extending previous work lossy [S. Franke et al., Phys. Rev. Lett. 122, 213901 (2019)]. Applying a symmetrization transformation, show two fundamentally different ways constructing QNM photon Fock space, including (i) where there is separate operator basis both gain loss, (ii) degrees freedom are combined into...

10.1103/physreva.105.023702 article EN Physical review. A/Physical review, A 2022-02-02

We present a quantized quasinormal approach to rigorously describe coupled lossy resonators, and quantify the quantum coupling parameters as function of distance between resonators. also make direct connection classical modes theories, offering new unique insights into open cavity detailed calculations for microdisk resonators show striking interference effects that depend on phase modes, an effect is significant high quality factor modes. Our results demonstrate commonly adopted master...

10.1021/acsphotonics.1c01274 article EN ACS Photonics 2022-01-05

Alumina layers were grown from trimethylaluminum (TMA) and water, ozone as well an oxygen plasma co-reactants in low temperature spatial atomic layer deposition (ALD). The influence of the amount precursor, precursor exposure duration, substrate investigated with respect to growth rate while employing different sources. TMA/water process provided alumina (AlOx) films superb film quality shown by infrared measurements. Ozone-based processes allowed lower temperatures. Nevertheless, carbon...

10.1116/1.4971173 article EN Journal of Vacuum Science & Technology A Vacuum Surfaces and Films 2016-12-01

Chiral emission can be achieved from a circularly polarized dipole emitter in nanophotonic structure that possesses special polarization properties such as singularity, namely, with right or left (C-points). Recently, Chen et al. [Nature Physics 2020, 16, 571] demonstrated the surprising result of chiral radiation linearly (LP) and argued this effect is caused by decoupling underlying eigenmodes non-Hermitian system, working at an exceptional point (EP) region. Here we present quasinormal...

10.1021/acsphotonics.1c01848 article EN ACS Photonics 2022-03-09

The authors develop a regularized quasinormal-mode perturbation theory for quasinormal modes of leaky resonators, which can be used to predict the impact weak perturbations placed outside resonators interest. general method is then applied two illustrative examples, one-dimensional double-barrier system and three-dimensional plasmonic dimer structure.

10.1103/physreva.108.043502 article EN Physical review. A/Physical review, A 2023-10-04

We provide theory and formal insight on the Green function quantization method for absorptive dispersive spatial-inhomogeneous media in context of dielectric media. show that a fundamental identity, which appears, e.g., commutation relation electromagnetic fields, is also valid limit non-absorbing demonstrate how zero-point field fluctuations yields non-vanishing surface term configurations without absorption, when using more procedure method. then apply presented to recently developed...

10.1103/physrevresearch.2.033332 article EN cc-by Physical Review Research 2020-08-28

Using a rigorous mode theory for gain-compensated plasmonic dimers, we demonstrate how quality factors and Purcell can be dramatically increased, improving the from 10 to over 26,000 peak approximately 3000 billion. Full three-dimensional calculations are presented gold dimers in finite-size gain medium, which allows one easily surpass fundamental factor limits of lossy media. Within regime linear system response, show modified by contributions projected local density states as well...

10.1364/opticaq.504834 article EN cc-by Optica Quantum 2024-01-26

A multi-cavity quantization scheme is developed using quasinormal modes (QNMs) of optical cavities embedded in a homogeneous background medium for cases where retardation significant the inter-cavity coupling. Using quantities that can be calculated computational optics with numerical Maxwell solvers, we extend previous QNM schemes and define quantitative measure to determine if separate justified or joint system necessary. We test this examples two coupled one-dimensional dielectric slabs...

10.48550/arxiv.2404.07741 preprint EN arXiv (Cornell University) 2024-04-11

We introduce a theory to model spontaneous emission rates and the Purcell factor for linear gain media, including coupled loss cavity systems. demonstrate why usual Fermi's golden rule fails show impact of non-local term. how such effects with standard Maxwell calculation, which also exploits power quasinormal modes. As an application theory, we one can use compensation improve factors gold-dimer plasmon modes by over million fold.

10.1117/12.3026121 article EN 2024-08-02

A multicavity quantization scheme is developed using quasinormal modes (QNMs) of optical cavities embedded in a homogeneous background medium for cases where retardation significant the intercavity coupling. Using quantities that can be calculated computational optics with numerical Maxwell solvers, we extend previous QNM schemes and define quantitative measure to determine if separate justified or joint system necessary. We test this examples two coupled one-dimensional dielectric slabs...

10.1103/physreva.110.043718 article EN Physical review. A/Physical review, A 2024-10-23

In this study a high efficient p-i-n type orange organic light emitting diode (OLED) is presented. It based on doped charge transport layers to realize low operating voltage and layer which consists of alpha-NPD(4,4-bis [N-(1- naphtyl)-N-phenylamino]biphenyl) Iridium(III)bis(2-methyldibenzo-[f,h]quinoxaline)(acetylacetonate) as host phosphorescence dye dopant respectively. Organic are vacuum-sublimed ITO-coated glass substrates in vertical inline deposition tool, aluminium deposited directly...

10.1117/12.780430 article EN Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE 2008-04-07

Abstract Manufacturing of Organic Light Emitting Diodes (OLED) for lighting is still some distance from the industry recognized cost target 100 € /m 2 . Within government funded In‐Line (LILi) project, a team material supplier, machine manufacturers and basic researchers have investigated potential ways to reduce OLED manufacturing costs. The concept developed within LILi‐project shows that competitive structure can now be reached.

10.1002/j.2168-0159.2012.tb05940.x article EN SID Symposium Digest of Technical Papers 2012-06-01

In this paper, we derive a novel condition for single-resonance operation of microwave travelling-wave ring resonators which in contrast to the published derived from Su is valid ring's field multiplication factor M = S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">31</sub> . Unlike analyses available literature, analysis shown paper employs signal flow graphs, more flexible and allows account discontinuities with spatial expansion.

10.1109/eumc.2016.7824510 article EN 2016-10-01
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