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Superconducting nanowire single-photon detectors (SNSPDs) were integrated with plasmonic nanostructures to enhance the absorption efficiency of superconducting BSCCO stripes. A numerical investigation of optimized nanocavity array (NCAI) and nanocavity-trench-array (NCTAI) SNSPDs has revealed that more than one order of magnitude larger absorptance can be achieved at perpendicular incidence, when compared to the corresponding meandered BSCCO pattern in a resonant optical cavity. The SNSPDs were considerably improved either via first and third quarter cavity resonances, as evidenced by the near-field maps and validated by the standard retrieval method. Although, NCAI-SNSPD exhibits slightly larger absorptance, NCTAI-SNSPD remains competitive due to its larger period and significantly smaller filling factor, thereby allowing for quicker electric response., Comment: 6 pages, 4 Figures

Azimuthal orientation and handedness dependence of the optical responses, accompanied by asymmetric transmission and asymmetric dichroism, were demonstrated on multilayers constructed with subwavelength periodic arrays of Babinet complementary miniarrays, illuminated by linearly and circularly polarized light. In case of single-sided illumination asymmetric optical responses were observed at the spectral location of maximal cross-polarization that is accompanied by radiative electric dipoles on the nano-objects; whereas negative index material phenomenon was demonstrated, where the electric and magnetic dipoles overlap both spatially and spectrally. The NIM is accompanied by electric multipoles that add up non-radiatively and correlates with the magnetic dipoles characteristic on the nano-entities. By illuminating the multilayer with two counter-propagating circularly polarized beams it was proven that asymmetrical normal component displacement currents at the bounding interfaces arising along flat and tilted bands accompany the asymmetric co-polarized and cross-polarized transmission, respectively. The latter correlates with the asymmetric dichroism in the cross-polarized signal observed in case of single-sided circularly polarized light illumination. The dispersion maps in the single-sided asymmetrical co-polarized reflectance and absorptance indicate flat bands of analogous and complementary extrema, proving the dichroic nature of the observed asymmetric phenomena. The multilayer is proposed as an ultrathin NIM and nonreciprocal nanophotonic element.

Passive and active targets, implanted with gold nanoprisms, were designed to achieve enhanced and uniform power absorption during two-sided illumination by short laser pulses. The target length was adjusted to match the short laser pulse-length. Capabilities of three different, uniform, single-peaked Gaussian and adjusted, nanoresonator number density distributions were compared. The average local E-field inside the gain medium and on the surface of the nanoprisms were mapped as a function of the pump E-field strength and dye concentration, assuming a uniform nanoresonator distribution. The optimal parameters were adopted to each inspected nanoprism distributions. The time-evolution of the near-field enhancement (NFE), integrated power-loss and deposited energy were determined, additionally, the time-evolution of the standard deviation of these quantities was monitored. A comparative study was performed on passive and active targets, to determine the most advantageous nanoprism number density distribution type and to consider the advantages of dye doping. Based on the results, the adjusted distribution is proposed both in passive and active targets. Doping with the dye is advantageous in every inspected distribution in decreasing the minimal standard deviation of the NFE. It is advantageous in decreasing the delay of the minimal standard deviation in the power-loss and deposited energy, the standard deviation of the NFE as well as in increasing the FOM of the NFE in the uniform and adjusted distributions. In addition, doping allows for decreasing the delay of the minimal standard deviation in the NFE / increasing the mean NFE / decreasing the standard deviation of the power-loss and deposited energy in the uniform / Gaussian / adjusted distribution.

Active core-shell nanoresonators were designed in order to achieve large near-field enhancement, large power-outflow and minimal spaser threshold in the pump E-field strength. Gain-metal-dielectric (GMD) and gain-metal-gain (GMG) nanoresonator compositions were optimized with corresponding objective functions. The average local E-field, power-outflow and extinction cross-section were mapped above the pump E-field strength and dye concentration parameter plane with the criterion that the local E-field is smaller than the damage threshold of the nanoresonator. Regions, corresponding to the maxima in the average local E-field, the highest power-outflow, or to the zero-crossing of the extinction cross-section, were selected for detailed studies. The spectral distribution of the near-field enhancement, optical cross-sections, optical responses, quantum efficiencies, as well as the polar angle distribution of the far-field radiated power and the local charge distribution of dominant modes were inspected. Based on the results the GMD nanoresonator composition is proposed to maximize local E-field in near-field amplifiers, to maximize power-outflow in far-field-emitting lasers and to minimize threshold E-field in spasers. Comparing the complete characteristics, both compositions are suitable for different operation regions, the GMG is proposed as near-field amplifier and far-field out-coupling nanolaser, whereas the GMD is unambiguously preferable to achieve optimal spaser properties.

The geometry of various plasmonic nanoantennae was numerically optimized to maximize their sensitivity to the carrier envelope phase (CEP) of the exciting ultra-short laser pulses. To verify the CEP sensitivity, the near-field response of the investigated nanoantennae was analyzed by combining frequency and time-domain numerical computations. The simulation methodology, capable of accurately calculating the time-dependent photocurrent stem from optical field emission, enabled the determination and optimization of all key parameters characterizing and governing the CEP dependence of the near-field responses. Three-types of structures were inspected, including individual triangular and teardrop-shaped nanoantennae and plasmonic lenses consisting of three hemispheres with gradually decreasing diameters. All structure types were optimized in solid and hollow compositions of gold nanoresonators as well. It was shown that hollow /solid singlets produce the largest /intermediate CEP dependent - to - CEP independent integrated current components' ratio, while their absolute CEP dependent integrated currents were the smallest /intermediate among the optimized structures. The highest /intermediate CEP sensitivity was achieved via solid plasmonic lenses due to their very large absolute CEP dependent integrated photocurrent originating from huge near-field enhancement in the nanogaps, while the integrated current components' ratio was smaller than for counterpart singlets.

Rapid recent development in laser technology and methods learned from relativistic heavy ion physics led to new possibilities for fusion. Using a Hydrogen rich UDMA-TEGDMA polymer fusion target, laser irradiation ionizes the target. If we implant nanoantennas into the target resonating to the laser light frequency massive number of electrons of the ionized plasma resonate within the nanoantenna forming a so called nanoplasmonic wave. Our kinetic model simulation with a Hydrogen target indicates that the field of these resonating electrons attracts and accelerates the surrounding protons of the plasma to multi-MeV energy. These protons are then energetic enough to achieve nuclear transmutation and fusion reactions. Without resonating nanoantenna there is no such collective proton acceleration, no energetic protons, and nuclear reactions at 30 mJ laser pulse energy., Comment: arXiv admin note: text overlap with arXiv:2212.03638

Recently laser induced fusion with simultaneous volume ignition, a spin-off from relativistic heavy ion collisions, was proposed, where implanted nanoantennas regulated and amplified the light absorption in the fusion target. Studies of resilience of the nanoantennas was published recently in vacuum. These studies are extended to nanoantennas embedded into a polymer, which modifies the nanoantenna's lifetime and absorption properties., Comment: 4 pages, 4 figures

Recently NAano-Plasmonic, Laser Inertial Fusion Experiments (NAPLIFE) were proposed, as an improved way to achieve laser driven fusion. The improvement is the combination of two basic research discoveries: (i) The possibility of detonations on space-time hyper-surfaces with time-like normal (i.e. simultaneous detonation in a whole volume) and (ii) to increase this volume to the whole target, by regulating the laser light absorption using nano-shells or nano-rods as antennas. These principles can be realized in an in-line, one dimensional configuration, in the simplest way with two opposing laser beams as in particle colliders. Such, opposing laser beam experiments were also performed recently. Here we study the consequences of the Laser Wake Field Acceleration (LWFA) if we experience it in a colliding laser beam set up. These studies can be applied to laser driven fusion, but also to other rapid phase transition, combustion, or ignition studies in other materials., Comment: 7 pages, 5 figures. arXiv admin note: text overlap with arXiv:2008.09847

Illumination of colloid sphere monolayers by circularly polarized beams enables the fabrication of concave patterns consisting of circular nanohole miniarrays that can be transferred into convex metal nanoparticle patterns via a lift-off procedure. Unique spectral and near-field properties are achievable by tuning the geometry of the central nanoring and quadrumer of slightly rotated satellite nanocrescents and by selecting those azimuthal orientations that promote localized plasmon resonances. The spectral and near-field effects of hexagonal patterns made of uniform gold nanorings and nanocrescents, that can be prepared by transferring masks fabricated by a perpendicularly and obliquely incident single homogeneous circularly polarized beam, were studied to uncover the supported localized plasmonic modes. Artificial rectangular patterns made of a singlet nanoring and singlet nanocrescent as well as quadrumer of four nanocrescents were investigated to analyze the role of nano-object interactions and lattice type. It was proven that all nanophotonical phenomena are governed by the azimuthal orientation independent localized resonance on the nanorings and by the C2, C1 and U resonances on the nanocrescents in case of $\bar{E}$-field oscillation direction perpendicular and parallel to their symmetry axes. The interaction between localized surface plasmon resonances on individual nano-objects is weak, whereas scattered photonic modes have a perturbative role at the Rayleigh anomaly only on the larger periodic rectangular pattern of miniarrays. Considerable fluorescence enhancement of dipolar emitters is achievable at spectral locations promoting the C and U resonances on the composing nano-objects., Comment: arXiv admin note: substantial text overlap with arXiv:2005.07616

Application of circularly polarized beams in interferometric illumination of colloid sphere monolayers enables the direct fabrication of rectangular patterns consisting of circular nanohole miniarrays in metal films. The spectral and near-field effects of complex rectangular patterns made of a central nanoring and slightly rotated satellite nanocrescents were studied in azimuthal orientations promoting the localized and propagating plasmon's coupling. To inspect the localized modes separately, spectral responses and near-field phenomena of hexagonal patterns composed of uniform nanorings and nanocrescents, that can be fabricated by a perpendicularly and obliquely incident single homogeneous circularly polarized beam, were investigated. To uncover the interaction of localized and propagating modes, artificial rectangular patterns composed of a singlet nanoring, singlet horizontal nanocrescent and quadrumer of four slightly rotated nanocrescents were analyzed. It was demonstrated that the interacting C2 and C1 localized resonances on the (approximately) horizontal nanocrescents in C orientation (($16^{\circ}$) $0^{\circ}$ azimuthal angle) and the azimuthal orientation (in)dependent localized resonance on the (nanorings) nanocrescents coupled with propagating surface plasmon polaritons (close to) in U orientation (($106^{\circ}$)$90^{\circ}$ azimuthal angle) result in similar split spectra. The spectral response of the complex miniarray pattern can be precisely tuned by varying the geometrical parameters of the moderately interacting nanoholes and the pattern period. Enhancement of dipolar emitter's fluorescence is demonstrated in appropriate configurations that have a potential application in bio-object detection.

Plasmonically enhanced fluorescence is a widely studied and applied phenomenon, however only a comparative theoretical and experimental analyses of coupled fluorophores and plasmonic nanoresonators makes it possible to uncover, how this phenomenon can be controlled. A numerical optimization method was applied to design configurations that are capable of resulting in an enhancement of excitation and emission, moreover of both phenomena simultaneously in coupled Cy5 dye molecule and gold nanorod systems. Parametric sensitivity studies revealed, how the fluorescence enhancement depends on the molecule's location, distance and orientation. Coupled systems designed for simultaneous improvement exhibited the highest (intermediate directional) total fluorescence enhancement, which is accompanied by intermediate sensitivity to the molecule's parameters, except the location and orientation sensitivity at the excitation wavelength. Gold nanorods with a geometry corresponding to the predicted optimal configurations were synthesized, and DNA strands were used to control the Cy5 dye molecule distance from the nanorod surface via hybridization of the Cy5-labelled oligonucleotide. State-of-the-art dSTORM microscopy was used to accomplish a proof-of-concept experimental demonstration of the theoretically predicted (directional) total fluorescence enhancement. The measured fluorescence enhancement was in good agreement with theoretical predictions, thus providing a complete kit to design and prepare coupled nanosystems exhibiting plasmonically enhanced fluorescence., Comment: 15 pages, 7 figures

Different types of concave plasmonic nanoresonators have been optimized to achieve superradiantly enhanced emission of SiV color centers in diamond. Comparative study has been performed to consider advantages of different N number of SiV color centers, different diamond-silver (bare) and diamond-silver-diamond (coated) core-shell nanoresonator types, as well as of spherical and ellipsoidal geometry. The complete fluorescence enhancement (qualified by Px factor) monitoring and the cQE corrected quantum efficiency weighted PxcQE objective function optimization promotes to design bad-cavities for plasmonic Dicke effect. The switching into a collective Dicke state via optimized nanoresonators results in a radiated power proportional to N^2, which manifest itself in an enhancement proportional to N both of the excitation and emission rates. Accordingly, enhancement proportional to N^2 of the Px factor and PxcQE has been reached both via four and six SiV color centers arranged in symmetrical square and hexagonal patterns inside all types of inspected nanoresonators. Coated spherical and bare ellipsoidal nanoresonators result in stronger non-cooperative fluorescence enhancement, while superradiance is better achieved via bare spherical nanoresonators independently of SiV color centers number, and via coated (bare) ellipsoidal nanoresonators seeded by four (six) SiV color centers. Indistinguishable superradiant state of four color centers and line-width narrowing is achieved via bare nanoresonators. Six color centers seeded bare spherical (ellipsoidal) nanoresonators result in larger fluorescence enhancement and more significantly overridden superradiance thresholds, while having slightly more (less) pronounced bad-cavity characteristics. Both phenomena are simultaneously optimized in ellipsoidal bare nanoresonators embedding six color centers with a slightly larger detuning., Comment: 14 pages, 5 figures in paper, 8 figures and corresponding tables in Supporting information

Optical response of silicon (SiV) and nitrogen (NV) vacancy diamond color centers coupled to silver and gold nanorod dimers was numerically inspected. Optimization of the coupled emitter - nanorod dimer configurations was performed to attain the highest possible fluorescence enhancement by enhancing the excitation and emission of color centers simultaneously through plasmonic antenna resonances. To minimize losses conditional optimization was realized by setting a criterion regarding the minimum quantum efficiency of the coupled system (cQE). Restricted symmetric and allowed asymmetric antenna designs were also inspected to prove the potential advantages of asymmetric configurations tuneability. Among all inspected systems the highest 2.59*10^8 fluorescence enhancement with 46.08% cQE was achieved in case of NV color center coupled to asymmetric silver nanoantenna dimer. This is 3.17-times larger than the enhancement in corresponding symmetric configuration, which has larger 68.52% cQE. In case of SiV color center the highest 1.04*10^8 fluorescence enhancement with 37.83% cQE was achieved via asymmetric silver nanoantenna dimer. This is 1.06-times larger than the enhancement in the corresponding symmetric configuration, which has larger 57.46% cQE. The highest fluorescence enhancement achieved by gold nanorods is 4.75*10^4 with 21.8% cQE, which was shown in case of SiV color center coupled to asymmetric dimer. The attained enhancement is 8.48- (92.42-) times larger than the fluorescence enhancement achievable via symmetric (asymmetric) gold nanorod dimer coupled to SiV (NV) color center., Comment: 17 pages, 8 figures

Configuration of three different concave silver core-shell nanoresonators was numerically optimized to enhance the excitation and emission of embedded silicon vacancy (SiV) diamond color centers simultaneously. According to the tradeoff between the radiative rate enhancement and quantum efficiency (QE) conditional optimization was performed to ensure ~2-3-4 and 5-fold apparent cQE enhancement of SiV color centers with ~10% intrinsic QE. The enhancement spectra, as well as the near-field and charge distribution were inspected to uncover the physics underlying behind the optical responses. The conditionally optimized coupled systems were qualified by the product of the radiative rate enhancements at the excitation and emission, which is nominated as Px factor. The optimized spherical core-shell nanoresonator containing a centralized emitter is capable of enhancing considerably the emission via bonding dipolar resonance. The Px factor is 529-fold with 49.7% cQE at the emission. Decentralization of the emitter leads to appearance of higher order multipolar modes, which is not advantageous caused by their nonradiative nature. Transversal and longitudinal dipolar resonances of the optimized ellipsoidal core-shell resonator were tuned to the excitation and emission, respectively. The simultaneous enhancements result in 6.2x10^5 Px factor with 50.6% cQE at the emission. Rod-shaped concave core-shell nanoresonators exploit similarly transversal and longitudinal dipolar resonances, moreover they enhance the fluorescence more significantly due to their antenna-like geometry. Px factor of 8.34x10^5 enhancement is achievable while the cQE is 50.3% at the emission. The enhancement can result in 2.03x10^6-fold Px factor, when the criterion regarding the minimum QE is set to 20%., Comment: 15 pages, 10 figures

Plasmonic biosensing chips were prepared by fabricating wavelength-scaled dielectric-metal interfacial gratings on polymer film covered bimetal layers. Lysozyme biomolecules (LYZ) and gold nanoparticle bioconjugates (AuNP-LYZ) with 1:5 mass ratio were seeded onto the biochip surfaces. Comparison of the reflectance curves measured in a modified Kretschmann arrangement and computed numerically proved that monitoring the narrower secondary peaks under optimal rotated-grating coupling condition makes it possible to achieve enhanced sensitivity in biodetection. The enlarged resonance peak shift is due to the horizontally and vertically antisymmetric long-range plamonic modes propagating at the edge of the valleys and hills, which originate from Bragg scattered surface plasmon polaritons. The sensitivity is further increased in case of bioconjugates due to the coupled localized resonances on Au NPs., Comment: 20 pages, 6 figures

A novel numerical methodology has been developed, which makes possible to optimize arbitrary emitting dipole and plasmonic nano-resonator configuration with an arbitrary objective function. By selecting quantum efficiency as the objective function that has to be maximized at preselected Purcell factor criteria, optimization of plasmonic nanorod based configurations has been realized to enhance fluorescence of NV and SiV color centers in diamond. Gold and silver nanorod based configurations have been optimized to enhance excitation and emission separately, as well as both processes simultaneously, and the underlying nanophotonical phenomena have been inspected comparatively. It has been shown that considerable excitation enhancement is achieved by silver nanorods, while nanorods made of both metals are appropriate to enhance emission. More significant improvement can be achieved via silver nanorods at both wavelengths of both color centers. It has been proven that theoretical limits originating from metal dielectric properties can be approached by simultaneous optimization, which results in configurations determined by preferences corresponding to the emission. Larger emission enhancement is achieved via both metals in case of SiV center compared to the NV center. Gold and silver nanorod based configurations making possible to improve SiV centers quantum efficiency by factors of 1.18 and 5.25 are proposed, which have potential applications in quantum information processing., Comment: 20 pages, 8 figures

Dispersion characteristics of four types of superconducting nanowire single photon detectors, nano-cavity-array- (NCA-), nano-cavity-deflector-array- (NCDA-), nano-cavity-double-deflector-array- (NCDDA-) and nano-cavity-trench-array- (NCTA-) integrated (I-A-SNSPDs) devices was optimized in three periodicity intervals commensurate with half-, three-quarter- and one SPP wavelength. The optimal configurations capable of maximizing NbN absorptance correspond to periodicity dependent tilting in S-orientation (90{\deg} azimuthal orientation). In NCAI-A-SNSPDs absorptance maxima are reached at the plasmonic Brewster angle (PBA) due to light tunneling. The absorptance maximum is attained in a wide plasmonic-pass-band in NCDAI_1/2*lambda-A, inside a flat-plasmonic-pass-band in NCDAI_3/4*lambda-A and inside a narrow plasmonic-band in NCDAI_lambda-A. In NCDDAI_1/2*lambda-A bands of strongly-coupled cavity and plasmonic modes cross, in NCDDAI_3/4*lambda-A an inverted-plasmonic-band-gap develops, while in NCDDAI_lambda-A a narrow plasmonic-pass-band appears inside an inverted-minigap. The absorptance maximum is achieved in NCTAI_1/2*lambda-A inside a plasmonic-pass-band, in NCTAI_3/4*lambda-A at inverted-plasmonic-band-gap center, while in NCTAI_lambda-A inside an inverted-minigap. The highest 95.05% absorptance is attained at perpendicular incidence onto NCTAI_lambda-A. Quarter-wavelength type cavity modes contribute to the near-field enhancement around NbN segments except in NCDAI_lambda-A and NCDDAI_3/4*lambda-A. The polarization contrast is moderate in NCAI-A-SNSPDs (~10^2), NCDAI- and NCDDAI-A-SNSPDs make possible to attain considerably large polarization contrast (~10^2-10^3 and ~10^3-10^4), while NCTAI-A-SNSPDs exhibit a weak polarization selectivity (~10-10^2)., Comment: 26 pages, 8 figures

Configurations capable of maximizing both absorptance and polarization contrast were determined for 1550 nm polarized light illumination of different plasmonic structure integrated superconducting nanowire single-photon detectors (SNSPDs) consisting of p=264 nm and P=792 nm periodic niobium-nitride (NbN) patterns on silica substrate. Global NbN absorptance maxima appear in case of p/s-polarized light illumination in S/P-orientation (gamma=90 azimuthal angle) and the highest polarization contrast is attained in S-orientation of all devices. Common nanophotonical origin of absorptance enhancement is collective resonance on nano-cavity-gratings with different profiles, which is promoted by coupling between localized modes in quarter wavelength MIM nano-cavities and laterally synchronized Brewster-Zenneck-type surface waves in integrated SNSPDs possessing a three-quarter-wavelength-scaled periodicity. The spectral sensitivity and dispersion characteristics reveal that device design specific optimal configurations exist., Comment: 21 pages, 9 figures

The optimal orientations are determined for polarized substrate side illumination of three superconducting nanowire single-photon detector (SNSPD) designs: (1) periodic niobium-nitride (NbN) stripes standing in air with dimensions according to conventional SNSPDs, (2) same NbN patterns below ~quarter-wavelength hydrogensilsesquioxane-filled nano-cavity, (3) analogous NbN patterns in HSQ nano-cavity closed by a thin gold reflector. Numerical computation results have shown that the optical response and near-field distribution vary significantly with polar-angle, fi, and these variations are analogous across all azimuthal-angles, gamma, but are fundamentally different in various device designs. Larger absorptance is available due to p-polarized illumination of NbN patterns in P-structure configuration, while s-polarized illumination results in higher absorptance in S-structure arrangement. As a result of p-polarized illumination a global maximum appears on absorptance of bare NbN pattern at polar angle corresponding to NbN-related ATIR; integration with HSQ nano-cavity results in a global absorptance maximum at polar angle corresponding to TIR at sapphire-air interface; while the highest absorptance is observable at perpendicular incidence on P-structures aligned below gold reflector covered HSQ nano-cavity. S-polarized light illumination results in a global absorptance maximum at TIR on bare NbN patterns; the highest absorptance is available below HSQ nano-cavity at polar angle corresponding to ATIR phenomenon; while the benefit of gold reflector is large and polar angle independent absorptance., Comment: 24 pages, 7 figures

An integrated interference and colloid sphere lithography (IICL) is presented to produce complex plasmonic structures consisting of wavelength-scaled periodic arrays of nano-objects with arbitrary array symmetry and controllable nano-scaled sub-structure. The IICL method is based on illumination of colloid sphere monolayers by interference patterns synchronized with sphere arrays along arbitrary crystallographic directions. This nano-kaleidoscope method enables to tune four structure parameters independently: the symmetry and characteristic periodicity of the interference pattern might be varied by the wavelength, number and angle of incidence of the interfering beams; the colloid-spheres' diameter-scaled distance between the nano-objects is controllable by the relative orientation of the interference pattern with respect to the hexagonal lattice of colloid spheres; the size of individual nano-objects is determined by the colloid-spheres diameter and by the light wavelength and is influenced by power density; the sub-structure size-parameter sensitively depends on the polarization state and can be tuned with the nano-object size simultaneously. Finite element method is applied to demonstrate the capabilities of IICL, and the impact of the resulted complex plasmonic patterns on spectral properties of thin gold films. The possibility to realize spectral engineering with predesigned rectangular arrays of hole-doublets that may be produced uniquely by IICL is shown., Comment: 12 pages, 5 figures

A novel finite-element method for calculating the illumination-dependence of absorption in three-dimensional nanostructures is presented based on the RF module of the COMSOL software package. This method is capable of numerically determining the optical response and near-field distribution of sub-wavelength periodic structures as a function of illumination orientations specified by polar angle, fi, and azimuthal angle, gamma. The method was applied to determine the illumination-angle-dependent absorptance in cavity-based superconducting-nanowire single-photon detector (SNSPD) designs. Niobium-nitride stripes based on dimensions of conventional SNSPDs and integrated with ~ quarter-wavelength hydrogensilsesquioxane-filled nano-optical cavities and covered by a thin gold film acting as a reflector were illuminated from below by p-polarized light in this study. The numerical results were compared to results from complementary transfer-matrix-method calculations on composite layers made of analogous film-stacks. This comparison helped to uncover the optical phenomena contributing to the appearance of extrema in the optical response. This paper presents an approach to optimizing the absorptance of different sensing and detecting devices via simultaneous numerical optimization of the polar and azimuthal illumination angles., Comment: 15 pages, 4 figures