262 citations · 1.2k across the 21 of their papers we have counts for
21 papers
Spectrally smooth broadband response via autocorrelation-constrained inverse design
Johannes Gedeon, Rasmus Ellebæk Christiansen, Ole Sigmund
Time-domain inverse design in photonics is known to be suitable for maximizing the efficiency of optical devices over broad frequency ranges. Objectives commonly used in this conte…
On performance bounds for topology optimization
Anna Dalklint, Rasmus E. Christiansen, Ole Sigmund
Topology optimization has matured to become a powerful engineering design tool that is capable of designing extraordinary structures and materials taking into account various physi…
Engineering optical forces through Maxwell stress tensor inverse design
Beñat Martinez de Aguirre Jokisch, Rasmus Ellebæk Christiansen, Ole Sigmund
Precise spatial manipulation of particles via optical forces is essential in many research areas, ranging from biophysics to atomic physics. Central to this effort is the challenge…
Orders-of-magnitude reduction in photonic mode volume by nano-sculpting
Rasmus E. Christiansen, Jesper Mørk, Ole Sigmund
Achieving strong light-matter interaction is important for studying and exploiting several physics phenomena. The light-matter interaction strength depends on the optical field int…
Omnidirectional gradient force optical trapping in dielectric nanocavities by inverse design
Beñat Martinez de Aguirre Jokisch, Benjamin Falkenberg Gøtzsche, Philip Trøst Kristensen +3
Optical trapping enables precise control of individual particles of different sizes, such as atoms, molecules, or nanospheres. Optical tweezers provide free-space omnidirectional o…
Designing Structures that Maximize Spatially Averaged Surface-Enhanced Raman Spectra
Wenjie Yao, Francesc Verdugo, Henry O. Everitt +2
We present a general framework for inverse design of nanopatterned surfaces that maximize spatially averaged surface-enhanced Raman (SERS) spectra from molecules distributed random…
Observation of strong backscattering in valley-Hall photonic topological interface modes
Christian Anker Rosiek, Guillermo Arregui, Anastasiia Vladimirova +4
The unique properties of light underpin the visions of photonic quantum technologies, optical interconnects, and a wide range of novel sensors, but a key limiting factor today is l…
Electronic-photonic circuit crossings
Babak Vosoughi Lahijani, Marcus Albrechtsen, Rasmus Christiansen +4
Electrical control of light in integrated photonics is central to a wide range of research and applications. It is conventionally achieved with thermo-optic tuning, but this suffer…
Trace formulation for photonic inverse design with incoherent sources
Wenjie Yao, Francesc Verdugo, Rasmus E. Christiansen +1
Spatially incoherent light sources, such as spontaneously emitting atoms, naively require Maxwell's equations to be solved many times to obtain the total emission, which becomes co…
Nanometer-scale photon confinement in topology-optimized dielectric cavities
Marcus Albrechtsen, Babak Vosoughi Lahijani, Rasmus Ellebæk Christiansen +8
Nanotechnology enables in principle a precise mapping from design to device but relied so far on human intuition and simple optimizations. In nanophotonics, a central question is h…
Towards 3D-Printed Inverse-Designed Metaoptics
Charles Roques-Carmes, Zin Lin, Rasmus E. Christiansen +5
Optical metasurfaces have been heralded as the platform to integrate multiple functionalities in a compact form-factor, potentially replacing bulky components. A central stepping s…
Topology Optimization of Surface-enhanced Raman Scattering Substrates
Ying Pan, Rasmus E. Christiansen, Jerome Michon +2
Surface-enhanced Raman spectroscopy is a powerful and versatile sensing method with a detection limit down to the single molecule level. In this article, we demonstrate how topolog…
Computational inverse design for ultra-compact single-piece metalenses free of chromatic and angular aberration
Zin Lin, Charles Roques-Carmes, Rasmus E. Christiansen +2
We present full-Maxwell topology-optimization design of a single-piece multlayer metalens, about 10 wavelengths~ in thickness, that simultaneously focuses over a angu…
Compact 200 line MATLAB code for inverse design in photonics by topology optimization: tutorial
Rasmus E. Christiansen, Ole Sigmund
We provide a compact 200 line MATLAB code demonstrating how topology optimization (TopOpt) as an inverse design tool may be used in photonics, targeting the design of two-dimension…
Inverse design in photonics by topology optimization: tutorial
Rasmus E. Christiansen, Ole Sigmund
Topology optimization methods for inverse design of nano-photonic systems have recently become extremely popular and are presented in various forms and under various names. Approac…
Fullwave Maxwell inverse design of axisymmetric, tunable, and multi-scale multi-wavelength metalenses
Rasmus E. Christiansen, Zin Lin, Charles Roques Carmes +5
We demonstrate new axisymmetric inverse-design techniques that can solve problems radically different from traditional lenses, including \emph{reconfigurable} lenses (that shift a…
Inverse Design of Nanoparticles for Enhanced Raman Scattering
Rasmus E. Christiansen, Jérôme Michon, Mohammed Benzaouia +2
We show that topology optimization (TO) of metallic resonators can lead to improvement in surface-enhanced Raman scattering (SERS) efficiency compared to traditio…
Strongly enhanced upconversion in trivalent erbium ions by tailored gold nanostructures: toward high-efficient silicon-based photovoltaics
Jeppe Christiansen, Joakim Vester-Petersen, Søren Roesgaard +6
Upconversion of sub-band-gap photons constitutes a promising way for improving the efficiency of silicon-based solar cells beyond the Shockley-Queisser limit. 1500 to 980 nm upconv…
Designing Photonic Topological Insulators with Quantum-Spin-Hall Edge States using Topology Optimization
Rasmus E. Christiansen, Fengwen Wang, Ole Sigmund +1
Designing photonic topological insulators is highly non-trivial because it requires inversion of band symmetries around the band gap, which was so far done using intuition combined…
Topological Insulators by Topology Optimization
Rasmus E. Christiansen, Fengwen Wang, Ole Sigmund
An acoustic topological insulator (TI) is synthesized using topology optimization, a free material inverse design method. The TI appears spontaneously from the optimization process…
Maximizing the quality factor to mode volume ratio for ultra-small photonic crystal cavities
Fengwen Wang, Rasmus Ellebæk Christiansen, Yi Yu +2
Small manufacturing-tolerant photonic crystal cavities are systematically designed using topology optimization to enhance the ratio between quality factor and mode volume, Q/V. For…