Micro/Nanophotonic Devices in Europe

A special issue of Micromachines (ISSN 2072-666X). This special issue belongs to the section "A:Physics".

Deadline for manuscript submissions: closed (31 January 2023) | Viewed by 27971

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Guest Editor
National Research Council (CNR), Institute of Applied Sciences and Intelligent Systems (ISASI), Via Pietro Castellino 111, 80131 Napoli, Italy
Interests: nonlinear optics; ultrafast optics; photonic devices
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Guest Editor
"Nello Carrara" Institute of Applied Physics—National Research Council (IFAC-CNR), I-50019 Firenze, Italy
Interests: glassy and nanostructured materials; integrated optics; optical microresonators; photonic devices
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Special Issue Information

Dear Colleagues,

The role of micro- and nanotechnologies in photonics has been growing fast in the last two decades, following a similar path as electronics in the previous years. If micro-optics made its first steps in the 1970s, with the developments of optical fibre systems and integrated optical waveguides, the beginning of nanophotonic may be associated with the discovery of photonic crystals at the end of 1980s. It is only after the beginning of this century, however, that micro- and nano-photonics have departed from their infancy and stepped into a new era, where they have fully shown their inclusive nature, providing the tools for innovative and sophisticated control of the properties of light at micro and nano scale. Thus, new or advanced structures and devices are being designed and implemented. Microresonators and metamaterials are only two examples of these advances.

Research in micro- and nano-photonics is now progressing in the academic and industrial laboratories worldwide. This Special Issue aims to highlight the results achieved in this area by European research. Many projects have been supported at a national or European level, and a good drive has also been provided by coordinating initiatives like Photonics21, the European Technology Platform which represents the photonics community of industry and research organisations, and the European Photonics Industry Consortium (EPIC). The goal of this Special Issue is to encompass recent significant studies and advances in the areas of micro- and nanophotonic devices. Analytical and numerical tools for design and modelling, advanced characterization and testing techniques, fabrication technologies and applications are all of interest.

Both theoretical and experimental articles in the following topics are welcome. Review papers and discussion papers, aiming at exploring future research directions, are welcome as well. The present list is not exhaustive and other topics related to micro- or nano-photonics can be considered.

Analytical and numerical design and simulation of photonic devices

Strong light–matter interactions at the nanoscale

Topological photonics

Nano-optomechanics

Metamaterials and metasurfaces

Nanostructured optical materials

Photonic and plasmonic nanomaterials

Optics and transport on 2D materials

Advanced spectroscopic techniques

Advanced imaging for photonic materials

Micro and nano fabrication technologies

Optical fibre devices

Optical waveguides and integrated photonics devices

Micro and nano resonators

Micro and nano light sources

Micro and nano light modulators and detectors

Photonic crystal devices

Nonlinear photonic micro and nano device

Photonic quantum devices

Micro and nano sensors

Micro and nano devices and systems for optical telecommunications

Micro and nano photonic devices and systems in biomedicine

Dr. Luigi Sirleto
Dr. Giancarlo C. Righini
Guest Editors

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Keywords

  • microphotonics
  • nanophotonics
  • photonic devices
  • photonic materials
  • quantum communications
  • European research

Published Papers (12 papers)

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Editorial

Jump to: Research, Review

6 pages, 447 KiB  
Editorial
Editorial for the Special Issue on Micro/Nanophotonic Devices in Europe
by Luigi Sirleto and Giancarlo C. Righini
Micromachines 2023, 14(4), 861; https://0-doi-org.brum.beds.ac.uk/10.3390/mi14040861 - 16 Apr 2023
Viewed by 831
Abstract
Photonics has often been defined as the key technology of the 21st century [...] Full article
(This article belongs to the Special Issue Micro/Nanophotonic Devices in Europe)
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Research

Jump to: Editorial, Review

21 pages, 8119 KiB  
Article
Signal-to-Noise Ratio Analysis for the Voltage-Mode Read-Out of Quartz Tuning Forks in QEPAS Applications
by Michele Di Gioia, Luigi Lombardi, Cristoforo Marzocca, Gianvito Matarrese, Giansergio Menduni, Pietro Patimisco and Vincenzo Spagnolo
Micromachines 2023, 14(3), 619; https://0-doi-org.brum.beds.ac.uk/10.3390/mi14030619 - 08 Mar 2023
Cited by 3 | Viewed by 1160
Abstract
Quartz tuning forks (QTFs) are employed as sensitive elements for gas sensing applications implementing quartz-enhanced photoacoustic spectroscopy. Therefore, proper design of the QTF read-out electronics is required to optimize the signal-to-noise ratio (SNR), and in turn, the minimum detection limit of the gas [...] Read more.
Quartz tuning forks (QTFs) are employed as sensitive elements for gas sensing applications implementing quartz-enhanced photoacoustic spectroscopy. Therefore, proper design of the QTF read-out electronics is required to optimize the signal-to-noise ratio (SNR), and in turn, the minimum detection limit of the gas concentration. In this work, we present a theoretical study of the SNR trend in a voltage-mode read-out of QTFs, mainly focusing on the effects of (i) the noise contributions of both the QTF-equivalent resistor and the input bias resistor RL of the preamplifier, (ii) the operating frequency, and (iii) the bandwidth (BW) of the lock-in amplifier low-pass filter. A MATLAB model for the main noise contributions was retrieved and then validated by means of SPICE simulations. When the bandwidth of the lock-in filter is sufficiently narrow (BW = 0.5 Hz), the SNR values do not strongly depend on both the operating frequency and RL values. On the other hand, when a wider low-pass filter bandwidth is employed (BW = 5 Hz), a sharp SNR peak close to the QTF parallel-resonant frequency is found for large values of RL (RL > 2 MΩ), whereas for small values of RL (RL < 2 MΩ), the SNR exhibits a peak around the QTF series-resonant frequency. Full article
(This article belongs to the Special Issue Micro/Nanophotonic Devices in Europe)
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12 pages, 3967 KiB  
Article
Bloch Surface Waves in Open Fabry–Perot Microcavities
by Niccolò Marcucci, Tian-Long Guo, Ségolène Pélisset, Matthieu Roussey, Thierry Grosjean and Emiliano Descrovi
Micromachines 2023, 14(3), 509; https://0-doi-org.brum.beds.ac.uk/10.3390/mi14030509 - 22 Feb 2023
Cited by 5 | Viewed by 2706
Abstract
Thanks to the increasing availability of technologies for thin film deposition, all-dielectric structures are becoming more and more attractive for integrated photonics. As light–matter interactions are involved, Bloch Surface Waves (BSWs) may represent a viable alternative to plasmonic platforms, allowing easy wavelength and [...] Read more.
Thanks to the increasing availability of technologies for thin film deposition, all-dielectric structures are becoming more and more attractive for integrated photonics. As light–matter interactions are involved, Bloch Surface Waves (BSWs) may represent a viable alternative to plasmonic platforms, allowing easy wavelength and polarization manipulation and reduced absorption losses. However, plasmon-based devices operating at an optical and near-infrared frequency have been demonstrated to reach extraordinary field confinement capabilities, with localized mode volumes of down to a few nanometers. Although such levels of energy localization are substantially unattainable with dielectrics, it is possible to operate subwavelength field confinement by employing high-refractive index materials with proper patterning such as, e.g., photonic crystals and metasurfaces. Here, we propose a computational study on the transverse localization of BSWs by means of quasi-flat Fabry–Perot microcavities, which have the advantage of being fully exposed toward the outer environment. These structures are constituted by defected periodic corrugations of a dielectric multilayer top surface. The dispersion and spatial distribution of BSWs’ cavity mode are presented. In addition, the hybridization of BSWs with an A exciton in a 2D flake of tungsten disulfide (WS2) is also addressed. We show evidence of strong coupling involving not only propagating BSWs but also localized BSWs, namely, band-edge and cavity modes. Full article
(This article belongs to the Special Issue Micro/Nanophotonic Devices in Europe)
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11 pages, 649 KiB  
Article
Meta-Atoms with Toroidal Topology for Strongly Resonant Responses
by Odysseas Tsilipakos, Zacharias Viskadourakis, Anna C. Tasolamprou, Dimitrios C. Zografopoulos, Maria Kafesaki, George Kenanakis and Eleftherios N. Economou
Micromachines 2023, 14(2), 468; https://0-doi-org.brum.beds.ac.uk/10.3390/mi14020468 - 17 Feb 2023
Cited by 1 | Viewed by 1527
Abstract
A conductive meta-atom of toroidal topology is studied both theoretically and experimentally, demonstrating a sharp and highly controllable resonant response. Simulations are performed both for a free-space periodic metasurface and a pair of meta-atoms inserted within a rectangular metallic waveguide. A quasi-dark state [...] Read more.
A conductive meta-atom of toroidal topology is studied both theoretically and experimentally, demonstrating a sharp and highly controllable resonant response. Simulations are performed both for a free-space periodic metasurface and a pair of meta-atoms inserted within a rectangular metallic waveguide. A quasi-dark state with controllable radiative coupling is supported, allowing to tune the linewidth (quality factor) and lineshape of the supported resonance via the appropriate geometric parameters. By conducting a rigorous multipole analysis, we find that despite the strong toroidal dipole moment, it is the residual electric dipole moment that dictates the electromagnetic response. Subsequently, the structure is fabricated with 3D printing and coated with silver paste. Importantly, the structure is planar, consists of a single metallization layer and does not require a substrate when neighboring meta-atoms are touching, resulting in a practical, thin and potentially low-loss system. Measurements are performed in the 5 GHz regime with a vector network analyzer and a good agreement with simulations is demonstrated. Full article
(This article belongs to the Special Issue Micro/Nanophotonic Devices in Europe)
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16 pages, 34120 KiB  
Article
Thermooptical PDMS-Single-Layer Graphene Axicon-like Device for Tunable Submicron Long Focus Beams
by Giancarlo Margheri, André Nascimento Barbosa, Fernando Lazaro Freire, Jr. and Tommaso Del Rosso
Micromachines 2022, 13(12), 2083; https://0-doi-org.brum.beds.ac.uk/10.3390/mi13122083 - 26 Nov 2022
Cited by 1 | Viewed by 1156
Abstract
Submicron long focusing range beams are gaining attention due to their potential applications, such as in optical manipulation, high-resolution lithography and microscopy. Here, we report on the theoretical and experimental characterization of an elastomeric polydimethylsiloxane/single layer graphene (PDMS/SLG) axicon-like tunable device, able to [...] Read more.
Submicron long focusing range beams are gaining attention due to their potential applications, such as in optical manipulation, high-resolution lithography and microscopy. Here, we report on the theoretical and experimental characterization of an elastomeric polydimethylsiloxane/single layer graphene (PDMS/SLG) axicon-like tunable device, able to generate diffraction-resistant submicrometric spots in a pump and probe configuration. The working principle is based on the phase change of an input Gaussian beam induced in the elastomer via the thermo-optical effect, while the heating power is produced by the optical absorption of the SLG. The phase-modified beam is transformed by an objective into a long focus with submicron diameter. Our foci reach an experimental full width at half maximum (FWHM) spot diameter of 0.59 μm at the wavelength of 405 nm, with the FWHM length of the focal line greater than 90 μm. Moreover, the length of the focal line and the diameter of the focus can be easily tuned by varying the pump power. The proposed thermo-optical device can thus be useful for the simple and cheap improvement of the spatial resolution on long focus lines. Full article
(This article belongs to the Special Issue Micro/Nanophotonic Devices in Europe)
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16 pages, 3392 KiB  
Article
A Miniaturized Device Coupled with Digital Image Correlation for Mechanical Testing
by Daniel J. Cruz, Jose Xavier, Rui L. Amaral and Abel D. Santos
Micromachines 2022, 13(11), 2027; https://0-doi-org.brum.beds.ac.uk/10.3390/mi13112027 - 19 Nov 2022
Cited by 2 | Viewed by 1408
Abstract
Miniaturized mechanical testing based on small sample testing technology is a powerful technique to characterize the mechanical properties of different materials, and it is being used in different application fields. However, the small size of the specimens poses several challenges because the results [...] Read more.
Miniaturized mechanical testing based on small sample testing technology is a powerful technique to characterize the mechanical properties of different materials, and it is being used in different application fields. However, the small size of the specimens poses several challenges because the results are highly sensitive to measurement accuracy and the corresponding mechanical properties can change substantially due to the so-called specimen size effect. In this work, a novel testing device based on miniaturized specimens is presented. The equipment is designed to test materials in tensile and compressive loadings, but it is also capable of performing reverse-loading tests. Buckling of the specimen is an inherent phenomenon in compression loadings, especially for thin materials. Therefore, specimen geometry is properly studied and optimized to mitigate this effect. To evaluate the deformation of the specimen, the digital image correlation (DIC) technique is used to capture the full-field strain in the central gauge section of the sample. A sensitivity analysis of the DIC setting parameters was performed for this application. To evaluate the performance of the developed system, experimental results of monotonic tests and tests with reverse loadings (tension-compression) are presented, considering two high-strength steels (DP500 and DP780). Full article
(This article belongs to the Special Issue Micro/Nanophotonic Devices in Europe)
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13 pages, 4034 KiB  
Article
Development of LCEs with 100% Azobenzene Moieties: Thermo-Mechanical Phenomena and Behaviors
by Domenico Sagnelli, Massimo Rippa, Amalia D’Avino, Ambra Vestri, Valentina Marchesano and Lucia Petti
Micromachines 2022, 13(10), 1665; https://0-doi-org.brum.beds.ac.uk/10.3390/mi13101665 - 03 Oct 2022
Cited by 8 | Viewed by 1245
Abstract
Azobenzene is one of the most investigated photo-responsive liquid crystalline molecules. It can isomerize between two different isoforms, trans (E) and cis (Z) configurations, when stimulated by light. It is used as a molecular engine in photo-mobile materials (PMPs). The use of liquid [...] Read more.
Azobenzene is one of the most investigated photo-responsive liquid crystalline molecules. It can isomerize between two different isoforms, trans (E) and cis (Z) configurations, when stimulated by light. It is used as a molecular engine in photo-mobile materials (PMPs). The use of liquid crystals (LCs) as building blocks enhances the mechanical properties of the PMPs. It is not easy to obtain PMPs with monodomain configurations when the LCs are 100% azobenzene. In this work, we studied three LC mixtures, describing the thermo/mechanical phenomena that regulate the actuation of such materials. The nematic temperature of the LC elastomers was measured and the PMPs carefully characterized for their bending and speed capability. Our finding suggests that the ratio between linear and cross-linker monomer greatly influences the nematic temperature of the mixture. Furthermore, 100% azobenzene materials polymerized using dicumyl peroxide can be useful to design polarization-selective switches. Full article
(This article belongs to the Special Issue Micro/Nanophotonic Devices in Europe)
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15 pages, 5245 KiB  
Article
Electrically Tunable Lens (ETL)-Based Variable Focus Imaging System for Parametric Surface Texture Analysis of Materials
by Jorabar Singh Nirwan, Shan Lou, Saqib Hussain, Muhammad Nauman, Tariq Hussain, Barbara R. Conway and Muhammad Usman Ghori
Micromachines 2022, 13(1), 17; https://0-doi-org.brum.beds.ac.uk/10.3390/mi13010017 - 23 Dec 2021
Cited by 2 | Viewed by 2944
Abstract
Electrically tunable lenses (ETLs) are those with the ability to alter their optical power in response to an electric signal. This feature allows such systems to not only image the areas of interest but also obtain spatial depth perception (depth of field, DOF). [...] Read more.
Electrically tunable lenses (ETLs) are those with the ability to alter their optical power in response to an electric signal. This feature allows such systems to not only image the areas of interest but also obtain spatial depth perception (depth of field, DOF). The aim of the present study was to develop an ETL-based imaging system for quantitative surface analysis. Firstly, the system was calibrated to achieve high depth resolution, warranting the accurate measurement of the depth and to account for and correct any influences from external factors on the ETL. This was completed using the Tenengrad operator which effectively identified the plane of best focus as demonstrated by the linear relationship between the control current applied to the ETL and the height at which the optical system focuses. The system was then employed to measure amplitude, spatial, hybrid, and volume surface texture parameters of a model material (pharmaceutical dosage form) which were validated against the parameters obtained using a previously validated surface texture analysis technique, optical profilometry. There were no statistically significant differences between the surface texture parameters measured by the techniques, highlighting the potential application of ETL-based imaging systems as an easily adaptable and low-cost alternative surface texture analysis technique to conventional microscopy techniques. Full article
(This article belongs to the Special Issue Micro/Nanophotonic Devices in Europe)
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9 pages, 489 KiB  
Article
Optical Fiber Sensor for Temperature and Strain Measurement Based on Multimode Interference and Square-Core Fiber
by Kun Wang, Xingchen Dong, Patrick Kienle, Maximilian Fink, Wolfgang Kurz, Michael H. Köhler, Martin Jakobi and Alexander W. Koch
Micromachines 2021, 12(10), 1239; https://0-doi-org.brum.beds.ac.uk/10.3390/mi12101239 - 13 Oct 2021
Cited by 10 | Viewed by 2059
Abstract
A variety of specialty fibers such as no-core fiber (NCF) have already been studied to reveal their sensing abilities. In this work, we investigate a specialty fiber, square-core fiber, for temperature and strain sensing. A simple single-mode–multimode–single-mode (SMS) fiber sensor was fabricated, consisting [...] Read more.
A variety of specialty fibers such as no-core fiber (NCF) have already been studied to reveal their sensing abilities. In this work, we investigate a specialty fiber, square-core fiber, for temperature and strain sensing. A simple single-mode–multimode–single-mode (SMS) fiber sensor was fabricated, consisting of a 30-cm-long square-core fiber. The experimental results indicate that the maximal wavelength-temperature and wavelength-strain sensitivities are −15.3 pm/C and −1.5 pm/με, respectively, while the maximal power-temperature and power-strain sensitivities are 0.0896 dBm/C and 0.0756 dBm/με. Analysis of the results suggests that the fiber sensor has the potential to be used as a high-sensitivity temperature sensor with a low strain sensitivity. Full article
(This article belongs to the Special Issue Micro/Nanophotonic Devices in Europe)
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Review

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30 pages, 6571 KiB  
Review
An Introduction to Nonlinear Integrated Photonics: Structures and Devices
by Luigi Sirleto and Giancarlo C. Righini
Micromachines 2023, 14(3), 614; https://0-doi-org.brum.beds.ac.uk/10.3390/mi14030614 - 07 Mar 2023
Cited by 4 | Viewed by 4816
Abstract
The combination of integrated optics technologies with nonlinear photonics, which has led to growth of nonlinear integrated photonics, has also opened the way to groundbreaking new devices and applications. In a companion paper also submitted for publication in this journal, we introduce the [...] Read more.
The combination of integrated optics technologies with nonlinear photonics, which has led to growth of nonlinear integrated photonics, has also opened the way to groundbreaking new devices and applications. In a companion paper also submitted for publication in this journal, we introduce the main physical processes involved in nonlinear photonics applications and discuss the fundaments of this research area. The applications, on the other hand, have been made possible by availability of suitable materials with high nonlinear coefficients and/or by design of guided-wave structures that can enhance a material’s nonlinear properties. A summary of the traditional and innovative nonlinear materials is presented there. Here, we discuss the fabrication processes and integration platforms, referring to semiconductors, glasses, lithium niobate, and two-dimensional materials. Various waveguide structures are presented. In addition, we report several examples of nonlinear photonic integrated devices to be employed in optical communications, all-optical signal processing and computing, or in quantum optics. We aimed at offering a broad overview, even if, certainly, not exhaustive. However, we hope that the overall work will provide guidance for newcomers to this field and some hints to interested researchers for more detailed investigation of the present and future development of this hot and rapidly growing field. Full article
(This article belongs to the Special Issue Micro/Nanophotonic Devices in Europe)
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25 pages, 2324 KiB  
Review
An Introduction to Nonlinear Integrated Photonics Devices: Nonlinear Effects and Materials
by Luigi Sirleto and Giancarlo C. Righini
Micromachines 2023, 14(3), 604; https://0-doi-org.brum.beds.ac.uk/10.3390/mi14030604 - 06 Mar 2023
Cited by 11 | Viewed by 3543
Abstract
The combination of integrated optics technologies with nonlinear photonics, which has led to the growth of nonlinear integrated photonics, has also opened the way to groundbreaking new devices and applications. Here we introduce the main physical processes involved in nonlinear photonics applications, and [...] Read more.
The combination of integrated optics technologies with nonlinear photonics, which has led to the growth of nonlinear integrated photonics, has also opened the way to groundbreaking new devices and applications. Here we introduce the main physical processes involved in nonlinear photonics applications, and we discuss the fundaments of this research area, starting from traditional second-order and third-order phenomena and going to ultrafast phenomena. The applications, on the other hand, have been made possible by the availability of suitable materials, with high nonlinear coefficients, and/or by the design of guided-wave structures, which can enhance the material’s nonlinear properties. A summary of the most common nonlinear materials is presented, together with a discussion of the innovative ones. The discussion of fabrication processes and integration platforms is the subject of a companion article, also submitted for publication in this journal. There, several examples of nonlinear photonic integrated devices to be employed in optical communications, all-optical signal processing and computing, or quantum optics are shown, too. We aimed at offering a broad overview, even if, certainly, not exhaustive. We hope that the overall work could provide guidance for those who are newcomers to this field and some hints to the interested researchers for a more detailed investigation of the present and future development of this hot and rapidly growing field. Full article
(This article belongs to the Special Issue Micro/Nanophotonic Devices in Europe)
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20 pages, 8154 KiB  
Review
Ge Ion Implanted Photonic Devices and Annealing for Emerging Applications
by Xingshi Yu, Xia Chen, Milan M. Milosevic, Weihong Shen, Rob Topley, Bigeng Chen, Xingzhao Yan, Wei Cao, David J. Thomson, Shinichi Saito, Anna C. Peacock, Otto L. Muskens and Graham T. Reed
Micromachines 2022, 13(2), 291; https://0-doi-org.brum.beds.ac.uk/10.3390/mi13020291 - 12 Feb 2022
Cited by 2 | Viewed by 2273
Abstract
Germanium (Ge) ion implantation into silicon waveguides will induce lattice defects in the silicon, which can eventually change the crystal silicon into amorphous silicon and increase the refractive index from 3.48 to 3.96. A subsequent annealing process, either by using an external laser [...] Read more.
Germanium (Ge) ion implantation into silicon waveguides will induce lattice defects in the silicon, which can eventually change the crystal silicon into amorphous silicon and increase the refractive index from 3.48 to 3.96. A subsequent annealing process, either by using an external laser or integrated thermal heaters can partially or completely remove those lattice defects and gradually change the amorphous silicon back into the crystalline form and, therefore, reduce the material’s refractive index. Utilising this change in optical properties, we successfully demonstrated various erasable photonic devices. Those devices can be used to implement a flexible and commercially viable wafer-scale testing method for a silicon photonics fabrication line, which is a key technology to reduce the cost and increase the yield in production. In addition, Ge ion implantation and annealing are also demonstrated to enable post-fabrication trimming of ring resonators and Mach–Zehnder interferometers and to implement nonvolatile programmable photonic circuits. Full article
(This article belongs to the Special Issue Micro/Nanophotonic Devices in Europe)
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