A mid-infrared focusing grating coupler with a single circular arc element based on germanium on silicon

• Xiaojun Zhu,
• Shuai Li,
• Ang Sun,
• Yongquan Pan,
• Wen Liu,
• Yue Wu,
• Guoan Zhang and
• Yuechun Shi

Beilstein J. Nanotechnol. 2023, 14, 478–484, doi:10.3762/bjnano.14.38

• cover the wavelength of 6–15 μm. Hence, it is a suitable material for biosensors applications in the MIR band [6]. In recent years, researchers have verified the feasibility of Ge MIR waveguides on various substrate materials, such as germanium on silicon (Ge-on-Si), germanium on silicon-on-insulator

• mass-produced integrated systems can be made from such platforms [6]. One key technology is how to couple the MIR light efficiently into the Ge-based waveguides. Many MIR grating couplers have been proposed and demonstrated to achieve this purpose [1][11]. In 2016, Alonso-Ramos et al. reported a Ge-on

Characterisation of a micrometer-scale active plasmonic element by means of complementary computational and experimental methods

• Ciarán Barron,
• Giulia Di Fazio,
• Samuel Kenny,
• Silas O’Toole,
• Robin O’Reilly and
• Dominic Zerulla

Beilstein J. Nanotechnol. 2023, 14, 110–122, doi:10.3762/bjnano.14.12

• microscopy (SJEM); surface plasmon polariton; Introduction Active plasmonics has been gaining attention from the research community for its role in the development of photonic devices [1][2], low-loss waveguides [3], and imaging systems [4]. It is an emerging subfield of plasmonics, which focuses on

Gap-directed chemical lift-off lithographic nanoarchitectonics for arbitrary sub-micrometer patterning

• Chang-Ming Wang,
• Hong-Sheng Chan,
• Chia-Li Liao,
• Che-Wei Chang and
• Wei-Ssu Liao

Beilstein J. Nanotechnol. 2023, 14, 34–44, doi:10.3762/bjnano.14.4

• with sharp edges originating from mathematical geometry designs, the results of this study are expected to have deep implications in the facile fabrication of plasmonic structures, waveguides, and diverse nanostructures. Experimental Materials and chemicals 11-Mercaptoundecanol (MCU), triethylene

• to other substrates for useful applications such as plasmonic signal enhancement, waveguides, and nanopores with specialized designs. This method is a large improvement over conventional soft lithographic techniques as the employment of minute gaps in collapsing stamps allow even finer patterns to be

Studies of probe tip materials by atomic force microscopy: a review

• Ke Xu and
• Yuzhe Liu

Beilstein J. Nanotechnol. 2022, 13, 1256–1267, doi:10.3762/bjnano.13.104

• new probe preparation method based on gold and silver nanowire optical waveguides, which uses the direct coupling of optical fiber and gold and silver optical waveguides to prepare the tip, synthesizes gold or silver nanowires by sol-gel method, etches the hollow optical fiber or pulls the cone by

Analytical and numerical design of a hybrid Fabry–Perot plano-concave microcavity for hexagonal boron nitride

• Felipe Ortiz-Huerta and
• Karina Garay-Palmett

Beilstein J. Nanotechnol. 2022, 13, 1030–1037, doi:10.3762/bjnano.13.90

• -defined spatio-temporal mode along with an accessible numerical aperture (NA) to increase the light extraction efficiency that is required for effective coupling into optical waveguides. Based on a previously developed experimental approach to fabricate hybrid Fabry–Perot microcavities (Ortiz-Huerta et al

Tunable high-quality-factor absorption in a graphene monolayer based on quasi-bound states in the continuum

• Jun Wu,
• Yasong Sun,
• Feng Wu,
• Biyuan Wu and
• Xiaohu Wu

Beilstein J. Nanotechnol. 2022, 13, 675–681, doi:10.3762/bjnano.13.59

• linear dispersion of the Dirac fermions [36]. These features proposed for graphene enable novel active devices, including modulators [37], perfect absorbers [38][39], imaging devices [40], detectors [41], waveguides [42][43], polarizers [44], and electromagnetic chirality devices [45]. The strength of

Alcohol-perturbed self-assembly of the tobacco mosaic virus coat protein

• Ismael Abu-Baker and
• Amy Szuchmacher Blum

Beilstein J. Nanotechnol. 2022, 13, 355–362, doi:10.3762/bjnano.13.30

• applications for helical and non-helical particles include templated waveguides and negative index materials [43][44]. High alcohol content can also cause aggregation of rod-shaped particles into large raft-like structures, which could allow for templating relatively large surface areas. The effect of alcohol

The patterning toolbox FIB-o-mat: Exploiting the full potential of focused helium ions for nanofabrication

• Victor Deinhart,
• Lisa-Marie Kern,
• Jan N. Kirchhof,
• Sabrina Juergensen,
• Joris Sturm,
• Enno Krauss,
• Thorsten Feichtner,
• Sviatoslav Kovalchuk,
• Michael Schneider,
• Dieter Engel,
• Bastian Pfau,
• Bert Hecht,
• Kirill I. Bolotin,
• Stephanie Reich and
• Katja Höflich

Beilstein J. Nanotechnol. 2021, 12, 304–318, doi:10.3762/bjnano.12.25

• standard use cases and lacks the flexibility to realize ultimate fidelity and robust large-area machining. So far, several patterning tools were developed, some of them only for specific photonic components, such as solid immersion lenses from diamond [8] or hole arrays and groove waveguides [9]. Others

Optically and electrically driven nanoantennas

• Monika Fleischer,
• Dai Zhang and
• Alfred J. Meixner

Beilstein J. Nanotechnol. 2020, 11, 1542–1545, doi:10.3762/bjnano.11.136

• the feed-gap is shown to couple to propagating modes in waveguides with up to 30% efficiency. Making use of propagating surface plasmon polaritons (SPPs), directional light beams are created in [57]. The SPPs are excited by inelastic tunneling from a scanning probe. The probe is positioned in the

Integrated photonics multi-waveguide devices for optical trapping and Raman spectroscopy: design, fabrication and performance demonstration

• Gyllion B. Loozen,
• Arnica Karuna,
• Mohammad M. R. Fanood,
• Erik Schreuder and
• Jacob Caro

Beilstein J. Nanotechnol. 2020, 11, 829–842, doi:10.3762/bjnano.11.68

• the influence of surfaces. We report the design (including simulations), fabrication and performance demonstration for multi-waveguide devices, using our Si3N4 waveguiding platform as the basis. The designed ridge waveguides, optimized for trapping and Raman spectroscopy, emit narrow beams. Multiple

• waveguides arranged around the central microbath result from fanning out of a single input waveguide using Y-splitters. A second waveguiding layer is implemented for detection of light scattered by the trapped particle. For reliable filling of the device with sample fluid, microfluidic considerations lead to

• waveguides. Keywords: Brownian motion; integrated optics devices; lab-on-a-chip; optical trapping; nanofabrication; Raman spectroscopy; ridge waveguides; Introduction Photonic lab-on-a-chip (LOC) techniques strongly attract attention for the manipulation and measurement of biological particles such as

Hexagonal boron nitride: a review of the emerging material platform for single-photon sources and the spin–photon interface

• Stefania Castelletto,
• Faraz A. Inam,
• Shin-ichiro Sato and
• Alberto Boretti

Beilstein J. Nanotechnol. 2020, 11, 740–769, doi:10.3762/bjnano.11.61

Plasmonic nanosensor based on multiple independently tunable Fano resonances

• Lin Cheng,
• Zelong Wang,
• Xiaodong He and
• Pengfei Cao

Beilstein J. Nanotechnol. 2019, 10, 2527–2537, doi:10.3762/bjnano.10.243

• optical phenomenon which occurs in the coupling of electromagnetic waves with free electrons at the metal–dielectric interface [1]. It can overcome the classical diffraction limit of light. Based on this property, metal–dielectric–metal (MDM) waveguides have been designed and widely applied to manipulate

• output waveguides are direct coupled to both ends of the resonator [3][8][9][10], second is that the resonators are side-coupled to one waveguide between the input and output ports [11][12][13][14][15], and third is that the input waveguide, output waveguide and resonators are all coupled through a gap

• waveguides. Normally, two or three different resonators are employed within a MDM waveguide environment, one of which effectively creates a continuous bright mode, and the other(s) discrete dark mode(s), or interference between different modes through the phase-coupling effect. The sharp response line of a

Abrupt elastic-to-plastic transition in pentagonal nanowires under bending

• Sergei Vlassov,
• Magnus Mets,
• Boris Polyakov,
• Jianjun Bian,
• Leonid Dorogin and
• Vahur Zadin

Beilstein J. Nanotechnol. 2019, 10, 2468–2476, doi:10.3762/bjnano.10.237

• conductive network [14][15][16]. Ag NWs are a promising material for flexible transparent electrodes [17]. Plasmon propagation and the optical properties of Ag and Au NWs make them attractive for nanophotonics as waveguides for visible light [18][19][20][21][22][23]. In all these applications, NWs may

Multiple Fano resonances with flexible tunablity based on symmetry-breaking resonators

• Xiao bin Ren,
• Kun Ren,
• Ying Zhang,
• Cheng guo Ming and
• Qun Han

Beilstein J. Nanotechnol. 2019, 10, 2459–2467, doi:10.3762/bjnano.10.236

• reflectance). In addition to PhC waveguides, metal–dielectric–metal (MDM) waveguides are very attractive for researchers because they can support surface plasmon polaritons (SPPs) and allow for the control of light at the subwavelength scale. MDM waveguides provide an effective approach to chip-scale photonic

• incoming and the outgoing waves in coupled waveguides satisfy the following relationships: where tm is the transmission coefficient for SPPs passing through the waveguide with a metal wall inside. It represents the direct coupling between input waveguide and output waveguide. If there is no metal wall in

Nonlinear absorption and scattering of a single plasmonic nanostructure characterized by x-scan technique

• Tushar C. Jagadale,
• Dhanya S. Murali and
• Shi-Wei Chu

Beilstein J. Nanotechnol. 2019, 10, 2182–2191, doi:10.3762/bjnano.10.211

• plasmonic nanostructures [4][5][6]. The potential applications of nonlinear nanoplasmonics include nanolasers [7], nanoantennas [8], surface plasmon polariton (SPP)-based waveguides [9], nanostructure-based optical limiters [10], nanoscopy instruments [11][12], and nanoelectronics as integrated optical

Liquid crystal tunable claddings for polymer integrated optical waveguides

• José M. Otón,
• Manuel Caño-García,
• Fernando Gordo,
• Eva Otón,
• Morten A. Geday and
• Xabier Quintana

Beilstein J. Nanotechnol. 2019, 10, 2163–2170, doi:10.3762/bjnano.10.209

• , Portugal Institute of Technical Physics, Wojskowa Akademia Techniczna, ul. Gen. Witolda Urbanowicza 2, 00-908 Warszawa, Poland 10.3762/bjnano.10.209 Abstract Optical waveguides in photonic integrated circuits are traditionally passive elements merely carrying optical signals from one point to another

• . These elements could contribute to the integrated circuit functionality if they were modulated either by variations of the core optical properties, or by using tunable claddings. In this work, the use of liquid crystals as electro-optically active claddings for driving integrated waveguides has been

• explored. Tunable waveguides have been modeled and fabricated using polymers. Optical functions such as variable coupling and optical switching have been demonstrated. Keywords: liquid crystal; organic waveguide; photonic integrated circuit; polymer waveguide; tunable cladding; Introduction Photonic

Nitrogen-vacancy centers in diamond for nanoscale magnetic resonance imaging applications

• Alberto Boretti,
• Lorenzo Rosa,
• Jonathan Blackledge and
• Stefania Castelletto

Beilstein J. Nanotechnol. 2019, 10, 2128–2151, doi:10.3762/bjnano.10.207

• magnetometry is discussed in [49], with record spatial localizations on the order of 10 nm in 3D and an inter-NV spacing down to 40 nm (20 nm inter-NV spacing length scale is needed for strong dipolar coupling). NV center specific ODMR coplanar waveguides (CPWs) are discussed in [50]. The authors achieve

Experimental study of an evanescent-field biosensor based on 1D photonic bandgap structures

• Jad Sabek,
• Francisco Javier Díaz-Fernández,
• Luis Torrijos-Morán,
• Zeneida Díaz-Betancor,
• Ángel Maquieira,
• María-José Bañuls,
• Elena Pinilla-Cienfuegos and
• Jaime García-Rupérez

Beilstein J. Nanotechnol. 2019, 10, 967–974, doi:10.3762/bjnano.10.97

• Mach–Zehnder interferometers or bimodal waveguides, respectively. By using this type of structures, outstanding results have been obtained for the specific detection of a wide range of analytes, reaching detect limits even below the nanogram-per-milliliter range for protein detection [5] and below the

Sub-wavelength waveguide properties of 1D and surface-functionalized SnO₂ nanostructures of various morphologies

• Venkataramana Bonu,
• Binaya Kumar Sahu,
• Arindam Das,
• Sankarakumar Amirthapandian,
• Sandip Dhara and
• Harish C. Barshilia

Beilstein J. Nanotechnol. 2019, 10, 379–388, doi:10.3762/bjnano.10.37

• Laboratories, Bangalore 560017, India Materials Physics Division, Indira Gandhi Center for Atomic Research, Homi Bhabha National Institute, Kalpakkam 603102, India 10.3762/bjnano.10.37 Abstract One-dimensional (1D) SnO2 sub-wavelength waveguides are a critical contribution to advanced optoelectronics. Further

• measurements and a band diagram is proposed. Keywords: functionalization; nanowires; photoluminescence; SnO2; sub-wavelength waveguide; Introduction The development and understanding of one-dimensional (1D) nanowire (NW) sub-wavelength waveguides is a crucial step towards on-chip routing of optical signals

• ]. Regarding the practicality of various dimensionalities, along with straight NWs, tapered waveguides have also been used for single photon generation and endoscopy [3][6]. Significant research interest has also been shown in the theoretical understanding of tapered waveguides. Calculations performed on

Magnetic-field sensor with self-reference characteristic based on a magnetic fluid and independent plasmonic dual resonances

• Kun Ren,
• Xiaobin Ren,
• Yumeng He and
• Qun Han

Beilstein J. Nanotechnol. 2019, 10, 247–255, doi:10.3762/bjnano.10.23

• , Tianjin 300222, China 10.3762/bjnano.10.23 Abstract A magnetic-field sensor with self-reference characteristic based on metal–dielectric–metal (MDM) plasmonic waveguides and a magnetic fluid (MF) is proposed and theoretically investigated. Independent dual resonances are supported by the coupled

• development of various integrated photonic components, such as filters [17], modulators [18], interferometers [19], optical switches [20] and nanosensors [21][22]. As important plasmonic structures, metal–dielectric–metal (MDM) waveguides have attracted considerable attention. Various kinds of plasmonic

• devices containing MDM waveguides have been investigated [23][24][25][26][27]. MDM waveguide–cavity coupled systems have been reported such as stub cavities [24], side-coupled rectangular cavities [25], T-shape cavities [26] and ring–groove joint cavities [27]. In this paper we propose a compact magnetic

High-throughput micro-nanostructuring by microdroplet inkjet printing

• Hendrikje R. Neumann and
• Christine Selhuber-Unkel

Beilstein J. Nanotechnol. 2018, 9, 2372–2380, doi:10.3762/bjnano.9.222

• : biofunctional surfaces; inkjet printing; microstructures; nanolithography; nanoparticles; Introduction Many applications require well-organized micro- and nanoscale patterning of metallic nanoparticles. Examples include high-performance optics [1], multimodal waveguides [2], biosensors [3] and biomaterials [4

Metal–dielectric hybrid nanoantennas for efficient frequency conversion at the anapole mode

• Valerio F. Gili,
• Lavinia Ghirardini,
• Davide Rocco,
• Giuseppe Marino,
• Ivan Favero,
• Iännis Roland,
• Giovanni Pellegrini,
• Lamberto Duò,
• Marco Finazzi,
• Luca Carletti,
• Andrea Locatelli,
• Aristide Lemaître,
• Dragomir Neshev,
• Costantino De Angelis,
• Giuseppe Leo and
• Michele Celebrano

Beilstein J. Nanotechnol. 2018, 9, 2306–2314, doi:10.3762/bjnano.9.215

• have already been achieved in integrated nonlinear optics [24], including SHG in quasi-phase-matched waveguides [25], efficient frequency-comb generation [25], and optical parametric oscillation [26]. Only very recently, thanks to the dramatic improvement of nanofabrication techniques, the integration

Optimization of the optical coupling in nanowire-based integrated photonic platforms by FDTD simulation

• Nan Guan,
• Andrey Babichev,
• Martin Foldyna,
• Dmitry Denisov,
• François H. Julien and
• Maria Tchernycheva

Beilstein J. Nanotechnol. 2018, 9, 2248–2254, doi:10.3762/bjnano.9.209

• communication systems are required [5][6]. The technology for visible wavelength PICs is much less mature than for IR PICs, and different approaches have been explored. One exploratory approach for visible photonics consists of the monolithic integration of InGaN emitters/detectors with GaN-based waveguides [7

• ][8][9]. This approach presents the advantage of providing both passive and active elements, however it brings many fabrication challenges (such as the necessity of low-loss GaN waveguides, etc). For passive photonic circuits used in the visible light range, SiN circuitry is gaining increasing

• extensive research on NW integrated platforms [28][29][30]. The first important step is the on-chip manipulation of light, which can be achieved by integrating NW emitters and detectors with waveguides. Park et al. demonstrated the coupling between an electrically pumped single InGaN/GaN NW LED and a 2D

Electromigrated electrical optical antennas for transducing electrons and photons at the nanoscale

• Arindam Dasgupta,
• Mickaël Buret,
• Nicolas Cazier,
• Marie-Maxime Mennemanteuil,
• Reinaldo Chacon,
• Kamal Hammani,
• Jean-Claude Weeber,
• Juan Arocas,
• Laurent Markey,
• Gérard Colas des Francs,
• Alexander Uskov,
• Igor Smetanin and
• Alexandre Bouhelier

Beilstein J. Nanotechnol. 2018, 9, 1964–1976, doi:10.3762/bjnano.9.187

• TiO2 waveguides and slot geometry. Electrically connected optical antennas on TiO2 waveguides Because the emission spans the visible part of the spectrum, and, depending on the underlying mechanism, extends to near-infrared wavelengths, standard silicon-based platforms are not adapted to collect and

• then used to remove the TiO2 layer and to define the waveguides. More details about this etching process can be found in [62]. A last optical lithography step is carried out to define the macroscopic leads that are connected to the microscopic electrodes. The process is subsequently terminated by

• nanowire. In Figure 6c and Figure 6e the waveguides have a cross section of 500 nm × 110 nm and both images were taken after creating the optical tunneling gap antennas. Note that in Figure 6e, the displacement of the junction towards the source electrode has been taken into account to place the tunneling

Tunable fractional Fourier transform implementation of electronic wave functions in atomically thin materials

• Daniela Dragoman

Beilstein J. Nanotechnol. 2018, 9, 1828–1833, doi:10.3762/bjnano.9.174

• implementation method of the FrFT of electron wave functions is based on the analogy between the classical electromagnetic field and the quantum wave function of ballistic electrons [11], as well as on the fact that the FrFT in optics can be implemented in graded index (GRIN) waveguides with a refractive index

• proposed already. For instance, it was shown that a tunable continuous FrFT of the wave function of a 2DEG can be obtained by applying an in-plane magnetic field [14], while a discrete Fourier transform based on an array of four quantum waveguides was demonstrated in [19]. The advantage of the proposal put