@article{WilsonGutscheHerrmannetal.2019, author = {Wilson, Jon and Gutsche, Philipp and Herrmann, Sven and Burger, Sven and McPeak, Kevin}, title = {Correlation of circular differential optical absorption with geometric chirality in plasmonic meta-atoms}, volume = {27}, journal = {Opt. Express}, doi = {10.1364/OE.27.005097}, pages = {5097}, year = {2019}, language = {en} } @article{GutscheMaeusleBurger2016, author = {Gutsche, Philipp and M{\"a}usle, Raquel and Burger, Sven}, title = {Locally Enhanced and Tunable Optical Chirality in Helical Metamaterials}, volume = {3}, journal = {Photonics}, arxiv = {http://arxiv.org/abs/1611.07748}, doi = {10.3390/photonics3040060}, pages = {60}, year = {2016}, language = {en} } @inproceedings{GutscheMaeusleBurger2016, author = {Gutsche, Philipp and M{\"a}usle, Raquel and Burger, Sven}, title = {Tailoring local optical chirality in helical metamaterials}, booktitle = {2016 10th International Congress on Advanced Electromagnetic Materials in Microwaves and Optics}, doi = {10.1109/MetaMaterials.2016.7746440}, pages = {73 -- 75}, year = {2016}, language = {en} } @misc{WilsonHerrmannGutscheetal.2016, author = {Wilson, Jon and Herrmann, Sven and Gutsche, Philipp and Burger, Sven and McPeak, Kevin}, title = {The Chiral Coefficient: Rapid Optimization of Broadband Plasmonic Chirality}, journal = {2016 MRS Fall Meeting \& Exhibit}, year = {2016}, language = {en} } @inproceedings{GutscheMaeusleBurger2016, author = {Gutsche, Philipp and M{\"a}usle, Raquel and Burger, Sven}, title = {Circular polarization phenomena in chiral nano-optical devices}, booktitle = {Light, Energy and the Environment 2016}, doi = {10.1364/FTS.2016.JW4A.4}, pages = {JW4A.4}, year = {2016}, language = {en} } @article{AbassGutscheMaesetal.2016, author = {Abass, Aimi and Gutsche, Philipp and Maes, Bjorn and Rockstuhl, Carsten and Martins, Emiliano R}, title = {Insights into directional scattering: from coupled dipoles to asymmetric dimer nanoantennas}, volume = {24}, journal = {Opt. Express}, number = {17}, doi = {10.1364/OE.24.019638}, pages = {19638 -- 19650}, year = {2016}, abstract = {Strong and directionally specific forward scattering from optical nanoantennas is of utmost importance for various applications in the broader context of photovoltaics and integrated light sources. Here, we outline a simple yet powerful design principle to perceive a nanoantenna that provides directional scattering into a higher index substrate based on the interference of multiple electric dipoles. A structural implementation of the electric dipole distribution is possible using plasmonic nanoparticles with a fairly simple geometry, i.e. two coupled rectangular nanoparticles, forming a dimer, on top of a substrate. The key to achieve directionality is to choose a sufficiently large size for the nanoparticles. This promotes the excitation of vertical electric dipole moments due to the bi-anisotropy of the nanoantenna. In turn, asymmetric scattering is obtained by ensuring the appropriate phase relation between the vertical electric dipole moments. The scattering strength and angular spread for an optimized nanoantenna can be shown to be broadband and robust against changes in the incidence angle. The scattering directionality is maintained even for an array configuration of the dimer. It only requires the preferred scattering direction of the isolated nanoantenna not to be prohibited by interference.}, language = {en} } @article{GutscheSantiagoSchneideretal.2020, author = {Gutsche, Philipp and Santiago, Xavier Garcia and Schneider, Philipp-Immanuel and McPeak, Kevin and Nieto-Vesperinas, Manuel and Burger, Sven}, title = {Role of Geometric Shape in Chiral Optics}, volume = {12}, journal = {Symmetry}, arxiv = {http://arxiv.org/abs/1808.01855}, doi = {10.3390/sym12010158}, pages = {158}, year = {2020}, language = {en} } @inproceedings{SchneiderSantiagoBinkowskietal.2018, author = {Schneider, Philipp-Immanuel and Santiago, Xavier Garcia and Binkowski, Felix and Gutsche, Philipp and H{\"o}hne, Theresa and Hammerschmidt, Martin and Zschiedrich, Lin and Burger, Sven}, title = {Light Management for Engineering Luminescence in Nanoscale Environments By Numerical Optimization}, volume = {16}, booktitle = {The Electrochemical Society, Meeting Abstracts}, issn = {2151-2043}, doi = {10.1149/MA2018-01/16/1164}, pages = {1164}, year = {2018}, language = {en} } @article{GregersendeLassonFrandsenetal.2018, author = {Gregersen, Niels and de Lasson, Jakob Rosenkrantz and Frandsen, Lars Hagedorn and Gutsche, Philipp and Burger, Sven and Kim, Oleksiy S. and Breinbjerg, Olav and Ivinskaya, Aliaksandra and Wang, Fengwen and Sigmund, Ole and H{\"a}yrynen, Teppo and Lavrinenko, Andrei}, title = {Benchmarking state-of-the-art numerical simulation techniques for analyzing large photonic crystal membrane line defect cavities}, volume = {10672}, journal = {Proc. SPIE}, doi = {10.1117/12.2304338}, pages = {106721C}, year = {2018}, language = {en} } @article{GutscheSchneiderBurgeretal.2018, author = {Gutsche, Philipp and Schneider, Philipp-Immanuel and Burger, Sven and Nieto-Vesperinas, Manuel}, title = {Chiral scatterers designed by Bayesian optimization}, volume = {963}, journal = {J. Phys.: Conf. Ser.}, arxiv = {http://arxiv.org/abs/1712.07091}, doi = {10.1088/1742-6596/963/1/012004}, pages = {012004}, year = {2018}, language = {en} } @article{GutscheNietoVesperinas2018, author = {Gutsche, Philipp and Nieto-Vesperinas, Manuel}, title = {Optical Chirality of Time-Harmonic Wavefields for Classification of Scatterers}, volume = {8}, journal = {Sci. Rep.}, arxiv = {http://arxiv.org/abs/1802.08029}, doi = {10.1038/s41598-018-27496-w}, pages = {9416}, year = {2018}, language = {en} } @misc{GutscheNietoVesperinasMaeusleetal.2017, author = {Gutsche, Philipp and Nieto-Vesperinas, Manuel and M{\"a}usle, Raquel and Burger, Sven}, title = {Chiral Nanophotonics: Theory and Simulation}, journal = {Doctoral Summer School on Nanophotonics and Metamaterials, ITMO University}, year = {2017}, abstract = {The interaction of light and chiral matter is subject of recent research both in fundamental science and applications. Among these are the helicity of electromagnetic fields described with the optical chirality density and emitters sensitive to circular polarization employed in quantum communications. In the weak coupling regime of chiral emitters, we analyze the conversion of chirality which can be regarded as an analogue to absorption of energy describing the change of circular polarization of the incident field. This enables the tailoring of chiral near-fields close to metamaterials, e.g. composed of gold helices, and gives insights into extinction measurements such as circular dichroism. We show relation of the weak and strong coupling regime. The latter can be modelled with cross electric-magnetic polarizabilities or with effective chiral materials, i.e. bi-anisotropic media. Accordingly, we motivate the necessity for rigorous numerical simulations to accurately describe chiral light-matter interaction.}, language = {en} } @misc{GutscheBurgerNietoVesperinas2017, author = {Gutsche, Philipp and Burger, Sven and Nieto-Vesperinas, Manuel}, title = {Fundamentals and Applications of an Optical Theorem for Chiral Optical Fields}, journal = {4th International Conference on Optical Angular Momentum}, year = {2017}, abstract = {The helicity of light is of great interest in both fundamental research and in applications such as dichroism spectroscopy. Its time-harmonic formulation is directly proportional to the density of optical chirality. Recently, both an helicity optical theorem (HOT) and a chirality conservation law (CCL) have been formulated for arbitrary scatterers taking into account an underlying continuity equation of this quantity. We summarize these two equivalent fundamental laws and analyze their potential applications.}, language = {en} } @misc{Gutsche2014, type = {Master Thesis}, author = {Gutsche, Philipp}, title = {Convergence Study of the Fourier Modal Method for Nano-optical Scattering Problems in Comparison with the Finite Element Method}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-56084}, pages = {87}, year = {2014}, abstract = {Nano-optical scattering problems play an important role in our modern, technologically driven society. Computers, smartphones and all kinds of electronic devices are manufactured by the semiconductor industry which relies on production using photomasks as well as optical process control. The digital world, e.g. the world wide web, is based on optical interconnects and so-called quantum computers based on optics are supposed to be next generation computers. Moreover, global economic progress demands new and sustainable energy resources and one option is to make use of the power stored in optical radiation from the sun. Additionally, understanding fundamental physics such as the optical properties of asymmetric, or chiral, structures could promote future innovations in engineering. In order to understand and manipulate these kinds of processes, physics provides a well established model: the so-called Maxwell's equations. Stated by James Clerk Maxwell in 1862, this description of the interaction of light and matter still provides a profound basis for the analysis of electromagnetic phenomena. However, real world problems cannot be calculated using simple mathematics. Rather, computer simulations are needed to obtain solutions of the physical model. Finding suitable methods to solve these problems opens up a wide variety of possibilities. On the one hand, there are methods which require long computing times. On the other hand, some algorithms depend on high memory usage. That is why the field of numerics deals with the question which method is optimally suited for specific problems. The aim of this work is to investigate the applicability of the so-called Fourier Modal Method (FMM) to nano-optical scattering problems in general. Since simple analytical solutions are non-existent for most recent physical problems, we use the Finite Element Method (FEM) to double-check performance of the FMM. Mathematics provide reliable procedures to control the errors of numerics using the FEM. Yet up to now it has not been possible to rigorously classify the quality of the Fourier Modal Method's results. It is not fully understood whether the process of investing more and more computing resources yields more accurate results. So, we have to ask ourselves: does the numerical method invariably converge? In spite of this uncertainty when using the FMM, it is a well established method dating back to the 1980s. This numerical method has recently been used to optimize performance of solar cells [19] as well as to improve the optical properties of so-called single-photon sources [41] which are essential for quantum cryptography. The latter is a promising candidate to increase digital security and revolutionise cryptography techniques. Furthermore, with the help of the Fourier Modal Method an important issue in optics has been partly resolved: angular filtering of light was made possible by using a mirror which becomes transparent at a certain viewing angle [77]. In addition, an improved numerical technique to design so-called Photonic Crystal waveguides based on the FMM was developed recently [15]. Photonic Crystals are used in the fields of optical bio-sensing and for the construction of novel semiconductor devices. Moreover, approaches to link the FMM and the FEM try to combine advantages of both methods to obtain fast and accurate results [81]. These ideas are closely linked to the well-known concept of Domain Decomposition within the FEM [88]. Here, one possibility to couple domains is to use the scattering matrix formalism as it is done in the FMM. In the scope of this convergence study, we state Maxwell's equations, particularly for periodic geometries. We describe two physical phenomena of nano-optics, namely chirality and opto-electrical coupling, and define the errors of our simulations. Afterwards, the two investigated methods are analysed with respect to their general properties and a way to unify modelling physics when using both algorithms is presented. With the help of various numerical experiments, we explore convergence characteristics of the FMM and draw conclusions about the ability of this approach to provide accurate results and, consequently, its potential for research on technological innovations.}, language = {en} } @inproceedings{PoulikakosGutscheMcPeaketal.2015, author = {Poulikakos, Lisa and Gutsche, Philipp and McPeak, Kevin and Burger, Sven and Niegemann, Jens and Hafner, Christian and Norris, David}, title = {A Far-Field Interpretation of Optical Chirality in Analogy to Poynting's Theorem}, booktitle = {META '15 Proceedings}, pages = {1215 -- 1216}, year = {2015}, abstract = {The optical chirality density is a valuable tool in locally characterizing chiral electromagnetic near-fields. However, how this quantity could translate into the far-field is not well understood. Here, we formulate a far-field interpretation of optical chirality by investigating its conservation law in isotropic media in analogy to Poynting's Theorem. We define the global chirality and find that lossy materials, in particular plasmonic nanostructures, can act as chirality generators. This can enable chiral sensing applications at the single molecule level.}, language = {en} } @misc{PoulikakosGutscheMcPeaketal.2015, author = {Poulikakos, Lisa and Gutsche, Philipp and McPeak, Kevin and Burger, Sven and Niegemann, Jens and Hafner, Christian and Norris, David}, title = {A Far-Field Interpretation of the Optical Chirality}, journal = {Frontiers in Nanophotonics (Congressi Stefano Franscini)}, year = {2015}, abstract = {A chiral structure is not super-imposable with its mirror image. Most commonly found in organic molecules, chirality can also occur in other systems, such as electromagnetic fields, where circularly polarized light is the most widespread example. Chiral electromagnetic fields can be a useful tool for biosensing applications. In particular, it has been shown that chiral plasmonic nanostructures have the ability to produce strongly enhanced chiral near-fields. Recently, our group has developed chiral plasmonic nanopyramids, which have the ability to focus chiral near-fields at their tip. This could enable chiral sensing at the single-molecule level. Chiral near-fields can be characterized in terms of the "optical chirality density". This time-even and parity-odd pseudoscalar was first derived by Lipkin and was found to follow a conservation law analogous to the energy conservation of electromagnetic fields. More recently, Tang and Cohen identified the physical meaning of the "optical chirality density" as the degree of asymmetry in the excitation rate of a chiral molecule. However, how this near-field interpretation of the optical chirality could translate into the far-field is not well understood. Here, we formulate a far-field interpretation by investigating the conservation law for optical chirality in matter, and performing time-averaging in analogy to Poynting's Theorem. In parallel to extinction energy, we define the "global chirality" as the sum of chirality dissipation within a material and the chirality flux leaving the system. With finite-element simulations, we place a dipole source at locations of enhanced local chirality and investigate the global chirality and ellipticity of emitted light in the far-field. Interestingly, we find that lossy materials with a complex dielectric function have the ability to generate global chirality when excited by achiral light. In particular, chiral plasmonic nanostructures are found to act as effective global chirality generators. The global interpretation of optical chirality provides a useful tool for biosensing applications with chiral plasmonic nanostructures, where the detection is routinely performed in the far-field.}, language = {en} } @inproceedings{GregersenRosenkrantzdeLassonHagedornFrandsenetal.2017, author = {Gregersen, Niels and Rosenkrantz de Lasson, Jakob and Hagedorn Frandsen, Lars and H{\"a}yrynen, Teppo and Lavrinenko, Andrei and Moerk, Jesper and Wang, Fengwen and Sigmund, Ole and Kim, Oleksiy S. and Breinbjerg, Olav and Ivinskaya, Aliaksandra and Gutsche, Philipp and Burger, Sven}, title = {Benchmarking five computational methods for analyzing large photonic crystal membrane cavities}, booktitle = {Numerical Simulation of Optoelectronic Devices (NUSOD)}, doi = {10.1109/NUSOD.2017.8010005}, pages = {89}, year = {2017}, language = {en} } @inproceedings{NovitskyRosenkrantzdeLassonHagedornFrandsenetal.2017, author = {Novitsky, Andrey and Rosenkrantz de Lasson, Jakob and Hagedorn Frandsen, Lars and Gutsche, Philipp and Burger, Sven and Kim, Oleksiy S. and Breinbjerg, Olav and Ivinskaya, Aliaksandra and Wang, Fengwen and Sigmund, Ole and H{\"a}yrynen, Teppo and Lavrinenko, Andrei and M{\o}rk, Jesper and Gregersen, Niels}, title = {Comparison of five computational methods for computing Q factors in photonic crystal membrane cavities}, booktitle = {19th International Conference on Transparent Optical Networks (ICTON)}, doi = {10.1109/ICTON.2017.8024813}, year = {2017}, language = {en} } @article{PoulikakosGutscheMcPeaketal.2016, author = {Poulikakos, Lisa and Gutsche, Philipp and McPeak, Kevin and Burger, Sven and Niegemann, Jens and Hafner, Christian and Norris, David}, title = {The Optical Chirality Flux as a Useful Far-Field Probe of Chiral Near Fields}, volume = {3}, journal = {ACS Photonics}, arxiv = {http://arxiv.org/abs/1601.06716}, doi = {10.1021/acsphotonics.6b00201}, pages = {1619}, year = {2016}, language = {en} } @misc{GutschePoulikakosBurgeretal.2016, author = {Gutsche, Philipp and Poulikakos, Lisa and Burger, Sven and Hammerschmidt, Martin and Schmidt, Frank}, title = {Optical chirality: conservation law in arbitrary space}, journal = {606. WE-Heraeus-Seminar on Nanophotonics and Complex Spatial Modes of Light}, year = {2016}, abstract = {The introduction of the near-field quantity of optical chirality has emerged in various numerical and few experimental studies of local chirality enhancement due to its relation to the excitation rate of chiral molecules. This time-even pseudoscalar has been dismissed as being a higher-order version of helicity. Nevertheless, we revisit the derivation of the underlying conservation law and define optical chirality in media similar to. We identify the mechanism of chirality conversion by either inhomogeneous or anisotropic space to complement the conservation of optical chirality. The conservation law of optical chirality in arbitrary space enables the extension of the concept of polarization to the near-field where no distiniguished propagation direction of light is present. We show that the connection of electromagnetic energy and optical chirality provide the ability to define a circular polarization basis in time-harmonic near-field analysis. In order to illustrate our theory, we present electromagnetic field simulations of simple as well as more complex nanostructures. Results using the well-known far-field polarization concept are readily reproduced and extended from the point of view of chirality conversion.}, language = {en} } @article{GutschePoulikakosHammerschmidtetal.2016, author = {Gutsche, Philipp and Poulikakos, Lisa and Hammerschmidt, Martin and Burger, Sven and Schmidt, Frank}, title = {Time-harmonic optical chirality in inhomogeneous space}, volume = {9756}, journal = {Proc. SPIE}, arxiv = {http://arxiv.org/abs/1603.05011}, doi = {10.1117/12.2209551}, pages = {97560X}, year = {2016}, language = {en} }