Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Naoya Tate Last modified date:2021.06.21

Associate Professor / Integrated Electronics / Department of Electronics / Faculty of Information Science and Electrical Engineering


Papers
1. Masaki Nakagawa, Yuki Miyata, Naoya Tate, Takahiro Nishimura, Suguru Shimomura, Sho Shirasaka, Jun Tanida, and Hideyuki Suzuki, Spatiotemporal model for FRET networks with multiple donors and acceptors: Multicomponent exponential decay derived from the master equation, Journal of the Optical Society of America B, 10.1364/JOSAB.410658, 38, 2, 294-299, 2021.01, [URL], In networks of spatially distributed fluorescent molecules, Förster resonance energy transfer (FRET) can simultaneously occur over multiple locations and times. Such “FRET networks” have great potential for information-processing and computing applications. To design these applications, the spatiotemporal behavior of FRET networks should be understood. However, studies on their spatiotemporal behavior are scarce. Here, we develop a spatiotemporal model for FRET networks and uncover its temporal characteristic behavior. We theoretically show that our model can generate a distinctive temporal behavior, i.e., the network-induced multicomponent exponential decay of the fluorescence intensity, even for FRET networks of fluorophores with an identical single exponential decay. This theoretical result is supported experimentally using quantum dots..
2. Suguru Shimomura, Takahiro Nishimura, Yuki Miyata, Naoya Tate, Yusuke Ogura, and Jun Tanida, Spectral and temporal optical signal generation using randomly distributed quantum dots, Optical Review, 10.1007/s10043-020-00588-7, 27, 264-269, 2020.03, [URL], Quantum dots (QDs) have a great potential for realizing information processing because of their signal-modulation capability based on energy transfer. We present a method for generating diverse temporal and spectral signals based on the energy transfer between multiple QDs. The method uses randomly distributed QDs, so it is not necessary to precisely arrange a QD network. With multiple energy transfers between QDs, a variety of signals within the QD network can be generated by optical inputs. Experimental results revealed that fluorescence decays of dense QDs were faster when the density of QDs or the irradiation intensity decreased. Furthermore, depending on the positions, stacked QDs showed different spectral responses. The randomly distributed QDs can generate diverse signals, which is essential for signal processing to handle temporal information..
3. Naoya Tate, Takashi Yatsui, Visible light-induced thymine dimerisation based on large localised field gradient by non-uniform optical near-field, Scientific Reports, 10.1038/s41598-019-54661-6, 9, 18383, 2019.12, [URL], The localised excitations of several molecular reactions utilising optical irradiation have been studied in the feld of molecular physics. In particular, deoxyribonucleic acid (DNA) strands organise the genetic information of all living matter. Therefore, artifcial methods for freely controlling reactions using only light irradiation are highly desirable for reactions of these strands; this in regard with artifcial protein synthesis, regional genetic curing, and stochastic analysis of several genetic expressions. Generally, DNA strands have strong absorption features in the deep ultra-violet (DUV) region, which are related to the degradation and reconstruction of the strand bonding structures. However, irradiation by DUV light unavoidably induces unintended molecular reactions which can damage and break the DNA strands. In this paper, we report a photo-induced molecular reaction initiated by the irradiation of DNA strands with visible light. We utilised photo-dissociation from the vibrational levels induced by non-uniform optical near-felds surrounding nanometric Au particles to which DNA strands were attached. The results were experimentally observed by a reduction in the DUV absorbance of the DNA strands during irradiation. There was a much higher yield of molecular reactions than expected due to the absorbance of visible light, and no defects were caused in the DNA strands..
4. Naoya Tate, Makoto Naruse, Nanoscale hierarchical optical interactions for secure information, Nanophotonics, 10.1515/nanoph-2016-0134, 6, 3, 613-622, 2017.05, We propose a novel method for observing and utilizing nanometrically fluctuating signals due to optical near-field interactions between a probe and target in near-field optical microscopy. Based on a hierarchical structure of the interactions, it is possible to obtain signals that represent two-dimensional spatial patterns without requiring any scanning process. Such signals reveal individual features of each target, and these features, when appropriately extracted and defined, can be used in security applications—an approach that we call nanophotonic security. As an experimental demonstration, output signals due to interactions between a SiO2 probe and Al nanorods were observed by using near-field optical microscopy at a single readout point, and these signals were quantitatively evaluated using an algorithm that we developed for extracting and defining features that can be used for security applications..
5. Naoya Tate, Tadashi Kawazoe, Wataru Nomura, Motoichi Ohtsu, Shunsuke Nakashima, Development of Zinc Oxide Spatial Light Modulator for High-Yield Speckle Modulation, IEICE Transactions on Electronics, 10.1587/transele.E99.C.1264, E99-C, 11, 1264-1270, 2016.11, In order to realize high-yield speckle modulation, we developed a novel spatial light modulator using zinc oxide single crystal doped with nitrogen ions. The distribution of dopants was optimized to induce characteristic optical functions by applying an annealing method developed by us. The device is driven by a current in the in-plane direction, which induces magnetic fields. These fields strongly interact with the doped material, and the spatial distribution of the refractive index is correspondingly modulated via external control. Using this device, we experimentally demonstrated speckle modulation, and we discuss the quantitative superiority of our approach..
6. Makoto Naruse, Morihisa Hoga, Yasuyuki Ohyagi, Shumpei Nishio, Naoya Tate, Naoki Yoshida, Tsutomu Matsumoto, Eigenanalysis of morphological diversity in silicon random nanostructures formed via resist collapse, Physica A: Statistical Mechanics and its Applications, 462, 883-888, 2016.11, Nano-artifact metrics is an information security principle and technology that exploits physically uncontrollable processes occurring at the nanometer-scale to protect against increasing security threats. Versatile morphological patterns formed on the surfaces of planar silicon devices originating from resist collapse are one of the most unique and useful vehicles for nano-artifact metrics. In this study, we demonstrate the eigenanalysis of experimentally fabricated silicon random nanostructures, through which the diversity and the potential capacity of identities are quantitatively characterized. Our eigenspace-based approach provides intuitive physical pictures and quantitative discussions regarding the morphological diversity of nanostructured devices while unifying measurement stability, which is one of the most important concerns regarding security applications. The analysis suggests approximately 10115 possible identities per 0.18-μm2 nanostructure area, indicating the usefulness of nanoscale versatile morphology. The presented eigenanalysis approach has the potential to be widely applicable to other materials, devices, and system architectures..
7. Tsutomu Matsumoto, Naoki Yoshida, Shumpei Nishio, Morihisa Hoga, Yasuyuki Ohyagi, Naoya Tate, Makoto Naruse, Optical nano artifact metrics using silicon random nanostructures, Scientific Reports, 10.1038/srep32438, 6, 32438, 2016.09, Nano-artifact metrics exploit unique physical attributes of nanostructured matter for authentication and clone resistance, which is vitally important in the age of Internet-of-Things where securing identities is critical. However, expensive and huge experimental apparatuses, such as scanning electron microscopy, have been required in the former studies. Herein, we demonstrate an optical approach to characterise the nanoscale-precision signatures of silicon random structures towards realising low-cost and high-value information security technology. Unique and versatile silicon nanostructures are generated via resist collapse phenomena, which contains dimensions that are well below the diffraction limit of light. We exploit the nanoscale precision ability of confocal laser microscopy in the height dimension; our experimental results demonstrate that the vertical precision of measurement is essential in satisfying the performances required for artifact metrics. Furthermore, by using state-of-the-art nanostructuring technology, we experimentally fabricate clones from the genuine devices. We demonstrate that the statistical properties of the genuine and clone devices are successfully exploited, showing that the liveness-detection-type approach, which is widely deployed in biometrics, is valid in artificially-constructed solid-state nanostructures. These findings pave the way for reasonable and yet sufficiently secure novel principles for information security based on silicon random nanostructures and optical technologies..
8. Wataru Nomura, Takashi Yatsui, Tadashi Kawazoe, Naoya Tate, Motoichi Ohtsu, High-speed flattening of crystallized glass substrates by dressed-photon-phonon etching, Applied Physics A: Materials Science & Processing, 10.1007/s00339-015-9466-8, 121, 4, 1403-1407, 2015.09, Dressed-photon–phonon (DPP) etching is a non-contact flattening technology that realizes ultra-flat surfaces and has been reported to achieve an arithmetic mean surface roughness, R a, on the order of 0.1 nm in various materials, such as fused silica, plastic films, and GaN crystal. In this study, we successfully flattened the surface of a crystallized glass substrate in several seconds using laser light with a higher power density than that used in previous studies. The target substrate had an initial appearance similar to frosted glass, with an R a of 92.5 nm. We performed DPP etching under a Cl2 atmosphere using a CW laser with a wavelength of 532 nm, a power of 8 W, and a spot diameter of 0.2 mm. After 1 s of processing, we obtained a flat surface with an R a of 5.00 nm. This surface roughness equaled or surpassed that of a substrate flattened by conventional chemical mechanical polishing, with an R a of 5.77 nm. Through the detailed analysis of atomic force microscopic images, we found the DPP etching resulted in the smaller standard deviation of the height difference than CMP in the smaller lateral size than 50 nm..
9. Naoya Tate, Tadashi Kawazoe, Wataru Nomura, Motoichi Ohtsu, Current-induced giant polarization rotation using a ZnO single crystal doped with nitrogen ions, Scientific Reports, 10.1038/srep12762, 5, 12762, 2015.08, Giant polarization rotation in a ZnO single crystal was experimentally demonstrated based on a novel phenomenon occurring at the nanometric scale. The ZnO crystal was doped with N+ and N2+ ions serving as p-type dopants. By applying an in-plane current using a unique arrangement of electrodes on the device, current-induced polarization rotation of the incident light was observed. From the results of experimental demonstrations and discussions, it was verified that this novel behavior originates from a specific distribution of dopants and the corresponding light–matter interactions in a nanometric space, which are allowed by the existence of such a dopant distribution..
10. Naoya Tate, Makoto Naruse, Tsutomu Matsumoto, Morihisa Hoga, Yasuyuki Ohyagi, Shumpei Nishio, Wataru Nomura, Motoichi Ohtsu, Non-scanning optical near-field microscopy for nanophotonic security, Applied Physics A: Materials Science & Processing, 121, 4, 1383-1387, 2015.07, We propose a novel method for observing and utilizing nanometrically fluctuating signals due to optical near-field interactions between a probe and target in near-field optical microscopy. Based on a hierarchical structure of the interactions, it is possible to obtain signals that represent two-dimensional spatial patterns without requiring any scanning process. Such signals reveal individual features of each target, and these features, when appropriately extracted and defined, can be used in security applications—an approach that we call nanophotonic security. As an experimental demonstration, output signals due to interactions between a SiO2 probe and Al nanorods were observed by using near-field optical microscopy at a single readout point, and these signals were quantitatively evaluated using an algorithm that we developed for extracting and defining features that can be used for security applications..
11. Ryuji Hirayama, Makoto Naruse, Hirotaka Nakayama, Naoya Tate, Atsushi Shiraki, Takashi Kakue, Tomoyoshi Shimobaba, Motoichi Ohtsu, Tomoyoshi Ito, Design, Implementation and Characterization of a Quantum-Dot-Based Volumetric Display, Scientific Reports, 10.1038/srep08472, 5, 8472, 1-6, 2015.02, [URL], In this study, we propose and experimentally demonstrate a volumetric display system based on quantum dots (QDs) embedded in a polymer substrate. Unlike conventional volumetric displays, our system does not require electrical wiring; thus, the heretofore unavoidable issue of occlusion is resolved because irradiation by external light supplies the energy to the light-emitting voxels formed by the QDs. By exploiting the intrinsic attributes of the QDs, the system offers ultrahigh definition and a wide range of colours for volumetric displays. In this paper, we discuss the design, implementation and characterization of the proposed volumetric display's first prototype. We developed an 8 × 8 × 8 display comprising two types of QDs. This display provides multicolour three-type two-dimensional patterns when viewed from different angles. The QD-based volumetric display provides a new way to represent images and could be applied in leisure and advertising industries, among others..