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

• , Nanjing University, Nanjing 210093, China 10.3762/bjnano.14.38 Abstract A mid-infrared (MIR) focusing grating coupler (FGC) with a single circular arc element (CAE) in the front of the gratings based on a germanium-on-silicon (Ge-on-Si) platform is designed and demonstrated. It can be used equivalently

• -silicon; mid-infrared; Introduction The mid-infrared (MIR) spectrum region covers the absorption band of most organic and inorganic matter. Thus, it has a broad application prospect in gas detection, environmental monitoring, lidar, free space optical communication, and remote sensing technologies [1][2

• ]. The recombination of chemical bonds caused by changes in molecular structures can induce significant differences in MIR spectra. Thus, slight differences in the structure of compounds or molecules (such as isomers) can be distinguished by mid-infrared spectroscopy [3]. Therefore, this spectral region

Numerical study on all-optical modulation characteristics of quantum cascade lasers

• Biao Wei,
• Haijun Zhou,
• Guangxiang Li and
• Bin Tang

Beilstein J. Nanotechnol. 2022, 13, 1011–1019, doi:10.3762/bjnano.13.88

• number of photons in the cavity of a mid-infrared QCL modulated with near-infrared optical injection. The results were consistent with an experiment, where the injected light increases the electron population and lifetime, but does not affect the optical gain obviously. Our study can be helpful for

• multiple nanostructures, which are grown by molecular beam epitaxy (MBE) [1]. It has been widely used in the fields of free space optical communication [2][3], gas detection [4][5], and biological research [6][7]. Because the QCL is a narrow linewidth and high-power laser working in the mid-infrared to

• , thus reducing the number of photons in the cavity and achieving modulation. Conclusion In this paper, to explore the phenomenon of all-optical modulation of QCLs, we studied the characteristics of a mid-infrared QCL using near-infrared optical injection of several mW at wavelengths of 820 nm and 1550

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

• interband contributions and is described by: Here, σintra and σinter are the intraband and interband conductivity, respectively. In the mid-infrared wavelength region considered in this work, the Fermi level is greater than half of the photon energy, that is, ℏω < 2Ef. Thus, the intraband contribution will

A new photodetector structure based on graphene nanomeshes: an ab initio study

• Babak Sakkaki,
• Hassan Rasooli Saghai,
• Ghafar Darvish and
• Mehdi Khatir

Beilstein J. Nanotechnol. 2020, 11, 1036–1044, doi:10.3762/bjnano.11.88

• . The results suggest that GNMs can be potentially used in mid-infrared detectors with specific detectivity values that are 100-fold that of graphene-based devices and 1000-fold that of GNR-based devices. Hence, the special properties of graphene combined with the quantum feathers of the perforation

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

• -free operation at 1.55 μm, ii) a high non-resonant quadratic susceptibility (d14 ≈ 100 pm/V for GaAs in the near infrared), and iii) a broad spectral window of transparency in the mid-infrared (up to 17 μm), which allows for the generation of intense second-order nonlinear optical effects. Many results

Surface-enhanced infrared absorption studies towards a new optical biosensor

• Lothar Leidner,
• Julia Stäb,
• Jennifer T. Adam and
• Günter Gauglitz

Beilstein J. Nanotechnol. 2016, 7, 1736–1742, doi:10.3762/bjnano.7.166

• -established in the visual regime, measures the optical thickness change of a sensitive layer caused, e.g., by binding an analyte. When operated in the mid-infrared range the sensor provides additional information via weak absorption spectra (fingerprints). The originally poor spectra are magnified by surface

• results are compared with a similar experiment performed with an ATR (attenuated total reflectance) set-up. Keywords: attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR); direct optical sensing; mid-infrared regime (MIR); reflectometric interference spectroscopy; surface

• many optical biosensors operating in the visible or near-infrared wavelength regimes with great success. Shifting the detection window to the mid-infrared (MIR) region has some advantages, but also creates many new problems to be solved. In his review article, Mizaikoff [5] asks the rhetorical question

Correlative infrared nanospectroscopic and nanomechanical imaging of block copolymer microdomains

• Benjamin Pollard and
• Markus B. Raschke

Beilstein J. Nanotechnol. 2016, 7, 605–612, doi:10.3762/bjnano.7.53

• simultaneously with AFM data channels [1]. For our s-SNOM experiments, we use a metallized scanning probe tip (11.72 N/m, PtSi–NCH, NanoWorld AG). Mid-infrared light tunable between 1660–1900 cm−1 from a quantum cascade laser (QCL, Daylight Solutions) is focused onto the tip, linearly polarized along the surface

Linear and nonlinear optical properties of hybrid metallic–dielectric plasmonic nanoantennas

• Mario Hentschel,
• Bernd Metzger,
• Bastian Knabe,
• Karsten Buse and
• Harald Giessen

Beilstein J. Nanotechnol. 2016, 7, 111–120, doi:10.3762/bjnano.7.13

• crystalline gallium arsenide substrate and have demonstrated enhanced second harmonic emission caused by the interplay of the local near-field of the split-ring resonator and the substrate. Recently, Alu and Belkin have reported similar results in the mid-infrared spectral region [70]. As a last example

Radiation losses in the microwave K_u band in magneto-electric nanocomposites

• Talwinder Kaur,
• Sachin Kumar,
• Jyoti Sharma and
• A. K. Srivastava

Beilstein J. Nanotechnol. 2015, 6, 1700–1707, doi:10.3762/bjnano.6.173

• to 32 nm (Table 1). Mid-infrared spectra analysis FTIR spectra have been recorded to identify molecular bands and functional groups (Figure 2) that are residues of the synthesis process. The relative intensities of peaks have slight variations but the peak positions remain unchanged with substitution

• , consequently, it can be used as radar-absorbing material. X-ray diffraction pattern of Ba1−xLaxCoxFe12−xO19/polyaniline composites: (a) x = 0.0 (COP), (b) x = 0.6 (CL6P), (c) x = 0.5 (CL5P) and (d) x = 0.1 (CL1P). Mid-infrared region spectra for composites COP, CL1P, Cl5P and CL6P. ESR spectra for (a) barium

Observation of a photoinduced, resonant tunneling effect in a carbon nanotube–silicon heterojunction

• Carla Aramo,
• Antonio Ambrosio,
• Michelangelo Ambrosio,
• Maurizio Boscardin,
• Paola Castrucci,
• Michele Crivellari,
• Marco Cilmo,
• Maurizio De Crescenzi,
• Francesco De Nicola,
• Emanuele Fiandrini,
• Valentina Grossi,
• Pasqualino Maddalena,
• Maurizio Passacantando,
• Sandro Santucci,
• Manuela Scarselli and
• Antonio Valentini

Beilstein J. Nanotechnol. 2015, 6, 704–710, doi:10.3762/bjnano.6.71

• allows the carriers to cross the junction through the 2.4 V barrier, even at voltages of a few hundred mV. The optoelectronic properties of semiconducting carbon nanotubes are advantageous for the development of photodetector devices in the near-to-mid-infrared region (from ≈1 to ≈15 μm) [8]. The

Anticancer efficacy of a supramolecular complex of a 2-diethylaminoethyl–dextran–MMA graft copolymer and paclitaxel used as an artificial enzyme

• Yasuhiko Onishi,
• Yuki Eshita,
• Rui-Cheng Ji,
• Masayasu Onishi,
• Takashi Kobayashi,
• Masaaki Mizuno,
• Jun Yoshida and
• Naoji Kubota

Beilstein J. Nanotechnol. 2014, 5, 2293–2307, doi:10.3762/bjnano.5.238

• complex and paclitaxel: (1) DDMC, (2) DDMC/PTX complex (DDMC 9.6 mg/PTX 0.385 mg), (3) DDMC/PTX complex (DDMC 9.6 mg/PTX 0.709 mg), and (4) PTX. Reprinted from [62]. IR absorption spectra of the DDMC–paclitaxel complex and paclitaxel. (a) Mid-infrared region (4.000–400 cm−1), (b) X–H stretching region: (1

FTIR nanobiosensors for Escherichia coli detection

• Stefania Mura,
• Gianfranco Greppi,
• Maria Laura Marongiu,
• Pier Paolo Roggero,
• Sandeep P. Ravindranath,
• Lisa J. Mauer,
• Nicoletta Schibeci,
• Francesco Perria,
• Massimo Piccinini,
• Plinio Innocenzi and
• Joseph Irudayaraj

Beilstein J. Nanotechnol. 2012, 3, 485–492, doi:10.3762/bjnano.3.55

• Discussion An optical biosensor was developed for the detection of pathogenic E. coli O157:H7, by using FTIR spectroscopy to provide mid-infrared fingerprints of pathogens present in buffer. The spectroscopic fingerprint of pathogens originates from the various functional groups related to proteins, lipids

• , and carbohydrates, and their mid-infrared (MIR) spectra can be used for the identification and structural characterization of different pathogens and subspecies [27]. MIR spectra are additive and sensitive, and allow the fingerprinting and quantification of the pathogen of interest, transforming the

Effect of deposition temperature on the structural and optical properties of chemically prepared nanocrystalline lead selenide thin films

• Anayara Begum,
• Amir Hussain and
• Atowar Rahman

Beilstein J. Nanotechnol. 2012, 3, 438–443, doi:10.3762/bjnano.3.50

• size [2][3]. PbSe has wide applications in long and mid-wavelength infrared detectors, optical amplifiers, mid-infrared lasers, as thermoelectric materials, and as Pb2+ ion selective sensors [4][5][6][7]. Among the various techniques used to prepare PbSe thin films, such as vacuum evaporation [8

Nano-FTIR chemical mapping of minerals in biological materials

• Sergiu Amarie,
• Paul Zaslansky,
• Yusuke Kajihara,
• Erika Griesshaber,
• Wolfgang W. Schmahl and
• Fritz Keilmann

Beilstein J. Nanotechnol. 2012, 3, 312–323, doi:10.3762/bjnano.3.35

• molecular vibrational absorption spectrum in the 3–30 µm wavelength region. Nano-FTIR spectroscopic near-field microscopy is a fascinating recent advance [2][3][4]. It enables scattering near-field optical microscopes (s-SNOM) [5][6] to operate at ultrahigh spatial resolution over a broad mid-infrared

• 128 × 128 sized image. Nano-FTIR mode of s-SNOM The nano-FTIR spectroscopic mode of s-SNOM uses illumination by a coherent broadband mid-infrared beam (here 25 µW) from a difference-frequency source [3] driven by a femtosecond (<100 fs) Er fiber laser (FFS.SYS-2B and FFS-CONT, toptica.com). Detection

Dense lying self-organized GaAsSb quantum dots on GaAs for efficient lasers

• Thomas H. Loeber,
• Dirk Hoffmann and
• Henning Fouckhardt

Beilstein J. Nanotechnol. 2011, 2, 333–338, doi:10.3762/bjnano.2.39

• GaAs wafers have received considerable attention in efforts to improve the efficiency of near- and mid-infrared antimonide lasers in the emission wavelength range between 1.0 and 1.5 μm [1]. The lattice mismatch of 7.8% between GaSb and GaAs (similar to that of InAs and GaAs) causes Stranski–Krastanov