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Marković I, Potrebić Ivaniš M, Tošić D. The Dynamic Tunability of Memristor-Based Active Filters. Micromachines (Basel) 2023; 14:2064. [PMID: 38004921 PMCID: PMC10673221 DOI: 10.3390/mi14112064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 10/29/2023] [Accepted: 11/02/2023] [Indexed: 11/26/2023]
Abstract
When the memristor was fabricated for the first time, it launched an entirely new field of research. Many of the published papers regarding memristors are primarily theoretical and are based on computer simulations. Some recent papers analyze the memristor's programming circuits, but to the best of the authors' knowledge, no memristor has been embedded into a commercial analog circuit. This paper is practically oriented and it is based on the experimental results obtained by measurements on the circuit prototype. We present a solution for automated programming of a commercially available memristor and its implementation in tunable active bandpass filter design. The novelty of this paper is that the active bandpass filter's central frequency could be programmed during the filter operation, so a pause for memristor state-switching is not required. The experimental results are promising, and open up possibilities for the memristor's application in analog systems.
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Affiliation(s)
- Ivo Marković
- Earth & Environmental Sciences Area, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA;
- School of Electrical Engineering, University of Belgrade, 110000 Belgrade, Serbia;
| | | | - Dejan Tošić
- School of Electrical Engineering, University of Belgrade, 110000 Belgrade, Serbia;
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Wang HZ, Li B. Effect of internal interface layer on dielectric properties of doped Ba 0.6Sr 0.4TiO 3thin films and its simulation in filters. J Phys Condens Matter 2023. [PMID: 37267987 DOI: 10.1088/1361-648x/acdb24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Effect of the internal interface layer on the dielectric properties of doped Ba0.6Sr0.4TiO3 (BST) films and their simulation research in filters. Based on the interfacial effect in the multi-layer ferroelectric thin film, a different number of internal interface layers was proposed and introduced into the Ba0.6Sr0.4TiO3 thin film. First, Ba0.6Sr0.4Ti0.99Zn0.01O3 (ZBST) sol and Ba0.6Sr0.4Ti0.99Mg0.01O3 (MBST) sols were prepared using the sol-gel method. Ba0.6Sr0.4Ti0.99Zn0.01O3/Ba0.6Sr0.4Ti0.99Mg0.01O3/Ba0.6Sr0.4Ti0.99Zn0.01O3 thin films with 2 layer internal interface layer, 4 layer internal interface layer and 8 layer internal interface layer were designed and prepared (S2, S4, S8). The effects of the internal interface layer on the structure, morphology, dielectric properties, and leakage current behavior of the films were studied. The results showed that all the films were of the cubic perovskite BST phase and had the strongest diffraction peak in the (110) crystal plane. The surface composition of the film was uniform, and there was no cracked layer. When the bias of the applied DC field was 600 kV/cm, the high-quality factor values of the S8 thin film at 10 MHz and 100 kHz were 111.3 and 108.6, respectively. The introduction of the internal interface layer changed the leakage current of the Ba0.6Sr0.4TiO3 thin film, and the S8 thin film exhibited the minimum leakage current density. The S8 thin-film capacitor was used as the tunable element to design a fourth-step "tapped" complementary bandpass filter. When the permittivity was reduced from 500 to 191, the central frequency-tunable rate of the filter was 5.7%.
Keyword: internal interface layer; alternately structured; tunable filter.
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Affiliation(s)
- Hong-Zhe Wang
- School of Electronic Information Engineering, Department of Electronic and Communication Engineering, Shanghai Dianji University, No.300 Shuihua Road, Pudong New Area, Shanghai, Shanghai, 201306, CHINA
| | - Bo Li
- School of Electronic Information Engineering, Department of Software Engineering, Shanghai Dianji University, No.300 Shuihua Road, Pudong New Area, Shanghai, Shanghai, 201306, CHINA
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Khasanov IS, Knyazev BA, Lobastov SA, Anisimov AV, Nikitin PA, Kameshkov OE. Optical Characterization of Thin Films by Surface Plasmon Resonance Spectroscopy Using an Acousto-Optic Tunable Filter. Materials (Basel) 2023; 16:1820. [PMID: 36902935 PMCID: PMC10004554 DOI: 10.3390/ma16051820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 02/20/2023] [Accepted: 02/21/2023] [Indexed: 06/18/2023]
Abstract
The paper presents the application of the acousto-optic tunable filter (AOTF) in surface plasmon resonance (SPR) spectroscopy to measure the optical thickness of thin dielectric coatings. The technique presented uses combined angular and spectral interrogation modes to obtain the reflection coefficient under the condition of SPR. Surface electromagnetic waves were excited in the Kretschmann geometry, with the AOTF serving as a monochromator and polarizer of light from a white broadband radiation source. The experiments highlighted the high sensitivity of the method and the lower amount of noise in the resonance curves compared with the laser light source. This optical technique can be implemented for nondestructive testing in the production of thin films in not only the visible, but also the infrared and terahertz ranges.
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Affiliation(s)
- Ildus Sh. Khasanov
- Scientific and Technological Centre of Unique Instrumentation RAS, 117342 Moscow, Russia
| | - Boris A. Knyazev
- Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk, Russia
| | - Sergey A. Lobastov
- Scientific and Technological Centre of Unique Instrumentation RAS, 117342 Moscow, Russia
| | - Alexander V. Anisimov
- Scientific and Technological Centre of Unique Instrumentation RAS, 117342 Moscow, Russia
| | - Pavel A. Nikitin
- Scientific and Technological Centre of Unique Instrumentation RAS, 117342 Moscow, Russia
| | - Oleg E. Kameshkov
- Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk, Russia
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Wang K, Wang Y, Guo X, Zhang Y, He A, Su Y. Ultracompact bandwidth- tunable filter based on subwavelength grating-assisted contra-directional couplers. Front Optoelectron 2021; 14:374-380. [PMID: 36637729 PMCID: PMC9743839 DOI: 10.1007/s12200-020-1056-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 09/02/2020] [Indexed: 06/17/2023]
Abstract
An ultracompact, bandwidth-tunable filter has been demonstrated using a silicon-on-insulator (SOI) wafer. The device is based on cascaded grating-assisted contra-directional couplers (GACDCs). It also involves the use of a subwavelength grating (SWG) structure. By heating one of the heaters on GACDCs, a bandwidth tunability of ∼6 nm is achieved. Owing to the benefit of having a large coupling coefficient between SWG and strip waveguides, the length of the coupling region is only 100 µm. Moreover, the combination of the curved SWG and the tapered strip waveguides effectively suppresses the sidelobes. The filter possesses features of simultaneous wavelength tuning with no free spectral range (FSR) limitation. A maximum bandwidth of 10 nm was experimentally measured with a high out-of-band contrast of 25 dB. Similarly, the minimum bandwidth recorded is 4 nm with an out-of-band contrast of 15 dB.
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Affiliation(s)
- Kangnian Wang
- State Key Laboratory of Advanced Optical Communication Systems and Networks, Department of Electronic Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Yuan Wang
- State Key Laboratory of Advanced Optical Communication Systems and Networks, Department of Electronic Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Xuhan Guo
- State Key Laboratory of Advanced Optical Communication Systems and Networks, Department of Electronic Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Yong Zhang
- State Key Laboratory of Advanced Optical Communication Systems and Networks, Department of Electronic Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - An He
- State Key Laboratory of Advanced Optical Communication Systems and Networks, Department of Electronic Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Yikai Su
- State Key Laboratory of Advanced Optical Communication Systems and Networks, Department of Electronic Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
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Aldrigo M, Dragoman M, Iordanescu S, Nastase F, Vulpe S. Tunable Microwave Filters Using HfO 2-Based Ferroelectrics. Nanomaterials (Basel) 2020; 10:E2057. [PMID: 33081017 DOI: 10.3390/nano10102057] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 10/02/2020] [Accepted: 10/14/2020] [Indexed: 11/17/2022]
Abstract
In this paper, we present microwave filters that are based on 6-nm-thick ferroelectric thin films of hafnium oxide doped with zirconium (HfZrO), which are tunable continuously in targeted bands of interest within the frequency range 0.1-16 GHz, when the applied direct current (DC) voltage is swept between 0 V and 4 V. Here, we exploit the orthorhombic polar phase in HfO2 through a careful doping using zirconium in an Atomic Layer Deposition (ALD) process, in order to guarantee phase stabilization at room temperature. Polarization versus voltage characterization has been carried out, showing a remanent polarization (Pr) of ~0.8 μC/cm2 and the coercive voltage at ~2.6 V. The average roughness has been found to be 0.2 nm for HfZrO films with a thickness of 6 nm. The uniform topography, without holes, and the low surface roughness demonstrate that the composition and the structure of the film are relatively constant in volume. Three filter configurations (low-pass, high-pass, and band-pass) have been designed, modelled, fabricated, and fully characterized in microwaves, showing a frequency shift of the minimum of the reflection coefficient between 90 MHz and 4.4 GHz, with a minimum insertion loss of approximately 6.9 dB in high-pass configuration.
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Deal J, Britain A, Rich T, Leavesley S. Excitation-Scanning Hyperspectral Imaging Microscopy to Efficiently Discriminate Fluorescence Signals. J Vis Exp 2019:10.3791/59448. [PMID: 31498305 PMCID: PMC6800214 DOI: 10.3791/59448] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Several techniques rely on detection of fluorescence signals to identify or study phenomena or to elucidate functions. Separation of these fluorescence signals were proven cumbersome until the advent of hyperspectral imaging, in which fluorescence sources can be separated from each other as well as from background signals and autofluorescence (given knowledge of their spectral signatures). However, traditional, emission-scanning hyperspectral imaging suffers from slow acquisition times and low signal-to-noise ratios due to the necessary filtering of both excitation and emission light. It has been previously shown that excitation-scanning hyperspectral imaging reduces the necessary acquisition time while simultaneously increasing the signal-to-noise ratio of acquired data. Using commercially available equipment, this protocol describes how to assemble, calibrate, and use an excitation-scanning hyperspectral imaging microscopy system for separation of signals from several fluorescence sources in a single sample. While highly applicable to microscopic imaging of cells and tissues, this technique may also be useful for any type of experiment utilizing fluorescence in which it is possible to vary excitation wavelengths, including but not limited to: chemical imaging, environmental applications, eye care, food science, forensic science, medical science, and mineralogy.
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Affiliation(s)
- Joshua Deal
- Department of Chemical and Biomolecular Engineering, University of South Alabama; Center for Lung Biology, University of South Alabama; Department of Pharmacology, University of South Alabama
| | - Andrea Britain
- Center for Lung Biology, University of South Alabama; Department of Pharmacology, University of South Alabama
| | - Thomas Rich
- Center for Lung Biology, University of South Alabama; Department of Pharmacology, University of South Alabama
| | - Silas Leavesley
- Department of Chemical and Biomolecular Engineering, University of South Alabama; Center for Lung Biology, University of South Alabama; Department of Pharmacology, University of South Alabama;
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Zhang M, Liu J, Cheng W, Cheng J, Zheng Z. A Tunable Optical Bragg Grating Filter Based on the Droplet Sagging Effect on a Superhydrophobic Nanopillar Array. Sensors (Basel) 2019; 19:s19153324. [PMID: 31362395 PMCID: PMC6696401 DOI: 10.3390/s19153324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 07/11/2019] [Accepted: 07/22/2019] [Indexed: 06/10/2023]
Abstract
Nanostructures have been widely applied on superhydrophobic surfaces for controlling the wetting states of liquid microdroplets. Many modern optic devices including sensors are also integrated with micro- or nanostructures for function enhancement. However, it is rarely reported that both microfluidics and optics are compatibly integrated in the same nanostructures. In this paper, a novel microfluidic-controlled tunable filter composed of an array of periodic micro/nanopillars on top of a planar waveguide is proposed and numerically simulated, in which the periodic pillars endow both the Bragg grating and the superhydrophobic functions. The tunability of grating is achieved by controlling the sagging depth of a liquid droplet into the periodic pillars. Simulation results show that a narrow bandwidth of 0.4 nm and a wide wavelength tuning range over 25 nm can be achieved by such a microfluidic-based tunable optofluidic waveguide Bragg grating filter. Moreover, this proposed scheme can be easily modified as a refractive index sensor with a sensitivity of 103 nm per refractive index unit.
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Affiliation(s)
- Meng Zhang
- School of Electronic and Information Engineering, Beihang University, 37 Xueyuan Rd, Beijing 100191, China
| | - Jiansheng Liu
- School of Electronic and Information Engineering, Beihang University, 37 Xueyuan Rd, Beijing 100191, China.
| | - Weifeng Cheng
- Department of Mechanical Engineering, Virginia Tech, 635 Prices Fork Road, Blacksburg, VA 24061, USA
| | - Jiangtao Cheng
- Department of Mechanical Engineering, Virginia Tech, 635 Prices Fork Road, Blacksburg, VA 24061, USA
| | - Zheng Zheng
- School of Electronic and Information Engineering, Beihang University, 37 Xueyuan Rd, Beijing 100191, China
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Kurihara J, Takahashi Y, Sakamoto Y, Kuwahara T, Yoshida K. HPT: A High Spatial Resolution Multispectral Sensor for Microsatellite Remote Sensing. Sensors (Basel) 2018; 18:E619. [PMID: 29463022 DOI: 10.3390/s18020619] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 02/10/2018] [Accepted: 02/15/2018] [Indexed: 11/17/2022]
Abstract
Although nano/microsatellites have great potential as remote sensing platforms, the spatial and spectral resolutions of an optical payload instrument are limited. In this study, a high spatial resolution multispectral sensor, the High-Precision Telescope (HPT), was developed for the RISING-2 microsatellite. The HPT has four image sensors: three in the visible region of the spectrum used for the composition of true color images, and a fourth in the near-infrared region, which employs liquid crystal tunable filter (LCTF) technology for wavelength scanning. Band-to-band image registration methods have also been developed for the HPT and implemented in the image processing procedure. The processed images were compared with other satellite images, and proven to be useful in various remote sensing applications. Thus, LCTF technology can be considered an innovative tool that is suitable for future multi/hyperspectral remote sensing by nano/microsatellites.
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Cu-Nguyen PH, Grewe A, Feßer P, Seifert A, Sinzinger S, Zappe H. An imaging spectrometer employing tunable hyperchromatic microlenses. Light Sci Appl 2016; 5:e16058. [PMID: 30167156 PMCID: PMC6059955 DOI: 10.1038/lsa.2016.58] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 11/23/2015] [Accepted: 12/04/2015] [Indexed: 05/29/2023]
Abstract
We present the design, fabrication and characterization of hydraulically-tunable hyperchromatic lenses for two-dimensional (2D) spectrally-resolved spectral imaging. These hyperchromatic lenses, consisting of a positive diffractive lens and a tunable concave lens, are designed to have a large longitudinal chromatic dispersion and thus axially separate the images of different wavelengths from each other. 2D objects of different wavelengths can consequently be imaged using the tunability of the lens system. Two hyperchromatic lens concepts are demonstrated and their spectral characteristics as well as their functionality in spectral imaging applications are shown.
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Affiliation(s)
- Phuong-Ha Cu-Nguyen
- Gisela and Erwin Sick Chair of Micro-optics, Department of Microsystems Engineering, University of Freiburg, Freiburg 79110, Germany
| | - Adrian Grewe
- Fachgebiet Technische Optik, Institut fur Mikro- und Nanotechnologien, Technische Universitat Ilmenau, Ilmenau 98684, Germany
| | - Patrik Feßer
- Fachgebiet Technische Optik, Institut fur Mikro- und Nanotechnologien, Technische Universitat Ilmenau, Ilmenau 98684, Germany
| | - Andreas Seifert
- Gisela and Erwin Sick Chair of Micro-optics, Department of Microsystems Engineering, University of Freiburg, Freiburg 79110, Germany
| | - Stefan Sinzinger
- Fachgebiet Technische Optik, Institut fur Mikro- und Nanotechnologien, Technische Universitat Ilmenau, Ilmenau 98684, Germany
| | - Hans Zappe
- Gisela and Erwin Sick Chair of Micro-optics, Department of Microsystems Engineering, University of Freiburg, Freiburg 79110, Germany
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Zhang Y, Hiroshima Y, Ma H, Zhang N, Zhao M, Hoffman RM. Complementarity of variable-magnification and spectral-separation fluorescence imaging systems for noninvasive detection of metastasis and intravital detection of single cancer cells in mouse models. Anticancer Res 2015; 35:661-667. [PMID: 25667443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Imaging of tumor growth, progression and metastasis with fluorescent proteins in mouse models is a powerful technology. A limit to fluorescent-protein imaging has been for non-invasive deep-seated tumors, such as those in the lung. In the present study, the Maestro spectral-separation fluorescence imaging system and the OV100 variable-magnification imaging system were compared for noninvasive detection of metastasis in fluorescent protein-expressing orthotopic lung, liver, pancreas, and colon cancer in nude mouse tumor models, as well as for intravital single-cell imaging. Sensitivity, multispectral capability, contrast, and single cell resolution were investigated. The Maestro system outperformed the OV100 for noninvasive imaging of primary and metastatic tumors. The Maestro system detected brain tumor metastasis five days earlier than did the OV100. The Maestro had greater depth of detection compared with the OV100. By separating skin and food autofluorescence, the Maestro provided high-contrast images. The Maestro system was able to produce composite images with more unmixed components and detected more different color signals simultaneously than did the OV100. However, the OV100 system had higher resolution and was able to detect single cells in vivo unlike the Maestro. The present study demonstrates that the two instruments are complementary for imaging of all stages of cancer in mice, including single-cell trafficking and the superiority of in vivo fluorescent-protein imaging over luciferase imaging.
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Affiliation(s)
- Yong Zhang
- AntiCancer, Inc., 7917 Ostrow Street, San Diego, CA, U.S.A
| | - Yukihiko Hiroshima
- AntiCancer, Inc., 7917 Ostrow Street, San Diego, CA, U.S.A. Department of Surgery, University of California, San Diego, CA, U.S.A. Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Huaiyu Ma
- AntiCancer, Inc., 7917 Ostrow Street, San Diego, CA, U.S.A
| | - Nan Zhang
- AntiCancer, Inc., 7917 Ostrow Street, San Diego, CA, U.S.A
| | - Ming Zhao
- AntiCancer, Inc., 7917 Ostrow Street, San Diego, CA, U.S.A
| | - Robert M Hoffman
- AntiCancer, Inc., 7917 Ostrow Street, San Diego, CA, U.S.A. Department of Surgery, University of California, San Diego, CA, U.S.A.
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