Publications
ResearcherID : C-5956-2008 (TY, h-index: 24) , AAZ-8749-2021 (RK, h-index: 11)
Google Scholar : TY (h-index: 34), RK (h-index: 11)
2007
Makoto Naruse, Takashi Yatsui, Kokoro Kitamura, Hirokazu Hori, Motoichi Ohtsu
Generating small-scale structures from large-scale ones via optical near-field interactions Journal Article
In: Optics Express, vol. 15, no. 19, pp. 11790-11797, 2007.
Abstract | Links | BibTeX | Tags: Nanophotonic fabrication, Near-field effect, Self-assembly
@article{Naruse:s,
title = {Generating small-scale structures from large-scale ones via optical near-field interactions},
author = {Makoto Naruse and Takashi Yatsui and Kokoro Kitamura and Hirokazu Hori and Motoichi Ohtsu},
doi = {10.1364/OE.15.011790},
year = {2007},
date = {2007-09-01},
urldate = {2007-09-01},
journal = {Optics Express},
volume = {15},
number = {19},
pages = {11790-11797},
publisher = {OSA},
abstract = {Optical near-fields, which appear in the vicinity of structures when irradiated with light, exhibit a hierarchical nature, meaning that the degree of localization of optical near-fields at a given point is related to the scale of the structure involved in this process. Therefore, if we could make optically induced fabrication processes selectively localized in the near-field region, we could generate a smaller-scale structure even from a larger-scale one via optical near-field interactions. We demonstrate the theoretical basis of this with an angular spectrum analysis of optical near-fields. We also experimentally demonstrate such principles by using ZnO nanoneedles fabricated through metal-organic vapor phase epitaxy (MOVPE) followed by a photo-induced MOVPE procedure where smaller-scale generated structures were clearly observed with the help of light irradiation. We also observed that the generated fine structures followed a power-law distribution, indicating that fractal structures emerged via optical near-field interactions.},
keywords = {Nanophotonic fabrication, Near-field effect, Self-assembly},
pubstate = {published},
tppubtype = {article}
}
Takashi Yatsui, Jungshik Lim, Tooru Nakamata, Kokoro Kitamura, Motoichi Ohtsu, Gyu-Chul Yi
Low-temperature (~270 oC) growth of vertically aligned ZnO nanorods using photoinduced metal organic vapour phase epitaxy Journal Article
In: Nanotechnology, vol. 18, no. 6, pp. 065606, 2007.
Abstract | Links | BibTeX | Tags: First, nanorod, Near-field effect, ZnO
@article{Yatsui_2007,
title = {Low-temperature (~270 oC) growth of vertically aligned ZnO nanorods using photoinduced metal organic vapour phase epitaxy},
author = {Takashi Yatsui and Jungshik Lim and Tooru Nakamata and Kokoro Kitamura and Motoichi Ohtsu and Gyu-Chul Yi},
doi = {10.1088/0957-4484/18/6/065606},
year = {2007},
date = {2007-02-01},
journal = {Nanotechnology},
volume = {18},
number = {6},
pages = {065606},
publisher = {IOP Publishing},
abstract = {We successfully produced a drastic decrease in the required growth temperature
of single-crystalline ZnO nanorods, and enabled successful growth of vertically
aligned ZnO nanorods on a Si(100) substrate using photoinduced metal organic
vapour phase epitaxy (MOVPE). We introduced 325 nm light during the MOVPE
growth, and achieved vertical growth of single-crystalline ZnO nanorods
with a hexagonal crystal structure on Si(100) at a growth temperature of
270 °C. The successful low-temperature growth of ZnO nanorods on the Si(100) substrate
described here is a promising step toward designing nanoscale photonic and electronic
devices required by future systems.},
keywords = {First, nanorod, Near-field effect, ZnO},
pubstate = {published},
tppubtype = {article}
}
of single-crystalline ZnO nanorods, and enabled successful growth of vertically
aligned ZnO nanorods on a Si(100) substrate using photoinduced metal organic
vapour phase epitaxy (MOVPE). We introduced 325 nm light during the MOVPE
growth, and achieved vertical growth of single-crystalline ZnO nanorods
with a hexagonal crystal structure on Si(100) at a growth temperature of
270 °C. The successful low-temperature growth of ZnO nanorods on the Si(100) substrate
described here is a promising step toward designing nanoscale photonic and electronic
devices required by future systems.
Takashi Yatsui, Suguru Sangu, Tadashi Kawazoe, Motoichi Ohtsu, Sung Jin An, Jinkyoung Yoo, Gyu-Chul Yi
Nanophotonic switch using ZnO nanorod double-quantum-well structures Journal Article
In: Applied Physics Letters, vol. 90, no. 22, pp. 223110, 2007.
Abstract | Links | BibTeX | Tags: First, Nanophotonic device, Selected, ZnO
@article{doi:10.1063/1.2743949,
title = {Nanophotonic switch using ZnO nanorod double-quantum-well structures},
author = {Takashi Yatsui and Suguru Sangu and Tadashi Kawazoe and Motoichi Ohtsu and Sung Jin An and Jinkyoung Yoo and Gyu-Chul Yi},
doi = {10.1063/1.2743949},
year = {2007},
date = {2007-01-01},
urldate = {2007-01-01},
journal = {Applied Physics Letters},
volume = {90},
number = {22},
pages = {223110},
abstract = {The authors report on time-resolved near-field spectroscopy of ZnO∕ZnMgO nanorod double-quantum-well structures (DQWs) for a nanometer-scale photonic device. They observed nutation of the population between the resonantly coupled exciton states of DQWs. Furthermore, they demonstrated switching dynamics by controlling the exciton excitation in the dipole-inactive state via an optical near field. The results of time-resolved near-field spectroscopy of isolated DQWs described here are a promising step toward designing a nanometer-scale photonic switch and related devices.},
keywords = {First, Nanophotonic device, Selected, ZnO},
pubstate = {published},
tppubtype = {article}
}
2006
Takashi Yatsui, Motoichi Ohtsu, Sung Jin An, Jinkyoung Yoo, Gyu-Chul Yi
In: Optical Review, vol. 13, no. 4, pp. 218-221, 2006.
Abstract | Links | BibTeX | Tags: First, nanorod, Near-field spectroscopy, ZnO
@article{2006yatsuiOptRev,
title = {Evaluating the quantum confinement effect of isolated ZnO nanorod single-quantum-well structures using near-field ultraviolet photoluminescence spectroscopy},
author = {Takashi Yatsui and Motoichi Ohtsu and Sung Jin An and Jinkyoung Yoo and Gyu-Chul Yi},
doi = {10.1007/s10043-006-0218-z},
year = {2006},
date = {2006-07-01},
journal = {Optical Review},
volume = {13},
number = {4},
pages = {218-221},
publisher = {Springer Nature},
abstract = {Using low-temperature near-field spectroscopy, we obtained spatially and spectrally resolved photoluminescence (PL) images of individual ZnO nanorod single-quantum-well structures (SQWs) with a spatial resolution of 20 nm. We observed the dependence of the quantum confinement effect of the PL peak on the well width (L aw), from which the linewidths of near-field PL spectra of ZnO nanorod SQWs (L aw = 2.5 and 3.75 nm) were determined to be as narrow as 3 meV. However, near-field PL spectra of individual SQWs with L aw = 5.0 nm exhibited two PL peaks, presumably due to strains or defects in the ZnMgO in the nanorod SQWs. Since the exciton in a quantum structure is an ideal two-level system with long coherence times, our results provide criteria for designing nanophotonic devices.},
keywords = {First, nanorod, Near-field spectroscopy, ZnO},
pubstate = {published},
tppubtype = {article}
}
Kokoro Kitamura, Takashi Yatsui, Motoichi Ohtsu
Near-field evaluation of a quantum size effect in self-aligned GaN whiskers fabricated by photochemical etching Journal Article
In: Optical Review, vol. 13, no. 4, pp. 222-224, 2006.
Abstract | Links | BibTeX | Tags: GaN, Photochemical etching, Whisker
@article{2006kitamuraOptRev,
title = {Near-field evaluation of a quantum size effect in self-aligned GaN whiskers fabricated by photochemical etching},
author = {Kokoro Kitamura and Takashi Yatsui and Motoichi Ohtsu},
doi = {10.1007/s10043-006-0222-3},
year = {2006},
date = {2006-07-01},
journal = {Optical Review},
volume = {13},
number = {4},
pages = {222-224},
publisher = {Springer Nature},
abstract = {We fabricated nanoscale GaN whiskers using photochemical etching. The fabricated GaN whiskers were conjugated and aligned perpendicular to the incident light polarization used for photochemical etching in a self-assembling manner. Their far-field photoluminescence spectra exhibited a blue-shifted photoluminescence peak at 3.60eV. Near-field photoluminescence spectra of individual GaN whiskers were obtained, for the first time. The evaluation of the near-field spectra identified several peaks from individual whiskers, corresponding to a diameter range of 5-10 nm, and revealed a stepwise change in the diameter along the axis of individual whisker.},
keywords = {GaN, Photochemical etching, Whisker},
pubstate = {published},
tppubtype = {article}
}
Tadashi Kawazoe, Takashi Yatsui, Motoichi Ohtsu
Nanophotonics using optical near fields Journal Article
In: Journal of Non-Crystalline Solids, vol. 352, no. 23, pp. 2492 - 2495, 2006, ISSN: 0022-3093, (review article).
Abstract | Links | BibTeX | Tags: Nanocrystals, Non-linear optics, QW, Review
@article{KAWAZOE20062492,
title = {Nanophotonics using optical near fields},
author = {Tadashi Kawazoe and Takashi Yatsui and Motoichi Ohtsu},
doi = {10.1016/j.jnoncrysol.2006.03.023},
issn = {0022-3093},
year = {2006},
date = {2006-07-01},
journal = {Journal of Non-Crystalline Solids},
volume = {352},
number = {23},
pages = {2492 - 2495},
abstract = {This paper introduces recent successes in nanophotonics utilizing local electromagnetic interactions between a few nanometric elements (i.e., the optical near-field interaction). The sections of this paper review nanophotonic devices, nanofabrication, and systems for operating nanophotonic devices efficiently. Using CuCl quantum dots, the operations of an optical switch measuring 20-nm in size (i.e., a nanophotonic switch) and a nanometric optical condenser, which attracts optical energy into a 10-nm spot (i.e., an optical nano-fountain), were verified experimentally. The power consumption of these devices is only 1/100000 that of conventional electronic devices. A nanodot coupler fabricated from a linear array of closely spaced metallic nanoparticles has also been introduced for transmitting an optical signal to a nanophotonic device. To increase the optical far- to near-field conversion efficiency for transmission, a surface plasmon polariton (SPP) condenser was fabricated from hemispherical metallic nanoparticles, so that it worked as a ‘phased array’. The SPP can be focused with a spot size as small as 400nm.},
note = {review article},
keywords = {Nanocrystals, Non-linear optics, QW, Review},
pubstate = {published},
tppubtype = {article}
}
Wataru Nomura, Motoichi Ohtsu, Takashi Yatsui
Efficient optical near-field energy transfer along an Au nanodot coupler with size-dependent resonance Journal Article
In: Applied Physics B, vol. 84, no. 1-2, pp. 257-259, 2006.
Abstract | Links | BibTeX | Tags: Plasmon
@article{2006nomuraAPB,
title = {Efficient optical near-field energy transfer along an Au nanodot coupler with size-dependent resonance},
author = {Wataru Nomura and Motoichi Ohtsu and Takashi Yatsui},
doi = {10.1007/s00340-006-2165-6},
year = {2006},
date = {2006-07-01},
journal = {Applied Physics B},
volume = {84},
number = {1-2},
pages = {257-259},
publisher = {Springer Nature},
abstract = {We confirmed that the light intensity (wavelength of 785 nm) scattered from an isolated hemispherical Au nanoparticle was resonantly enhanced at a diameter of 200 nm and a height of 50 nm, as observed experimentally using a collection-mode near-field optical microscope. The experimental results agreed with the calculated results using Mie's theory. Furthermore, we observed resonant energy transfer of the optical near-field energy along a chain of Au nanoparticles. The magnitude of the transferred energy increased resonantly at the size of resonant light scattering for an isolated Au nanoparticle (200 nm diameter with 240 nm center-to-center separation).},
keywords = {Plasmon},
pubstate = {published},
tppubtype = {article}
}
Takashi Yatsui, Yuuki Nakajima, Wataru Nomura, Motoichi Ohtsu
High-resolution capability of optical near-field imprint lithography Journal Article
In: Applied Physics B, vol. 84, no. 1-2, pp. 265-267, 2006.
Abstract | Links | BibTeX | Tags: First, Imprint, Nanophotonic fabrication, Near-field effect
@article{2006yatsuiAPBimprint,
title = {High-resolution capability of optical near-field imprint lithography},
author = {Takashi Yatsui and Yuuki Nakajima and Wataru Nomura and Motoichi Ohtsu},
doi = {10.1007/s00340-006-2328-5},
year = {2006},
date = {2006-07-01},
journal = {Applied Physics B},
volume = {84},
number = {1-2},
pages = {265-267},
publisher = {Springer Nature},
abstract = {We propose a novel method to increase the resolution of imprint lithography by introducing strong localization of the optical near-field intensity, depending on the mold structure. By optimizing the thickness of the metallic film on a SiO2 line-and-space (LS) mold without a sidewall coating, we confirmed that the optical near-field strongly localizes at the edge of the mold, using a finite-difference time-domain calculation method. Based on the calculated results, we performed optical near-field imprint lithography using a mold with metallized (20-nm-thick Al without a sidewall coating) SiO2 LS with a 300-nm half-pitch that was 200-nm deep with illumination using the g-line (wavelength of 436 nm), and obtained features as narrow as 50 nm wide.},
keywords = {First, Imprint, Nanophotonic fabrication, Near-field effect},
pubstate = {published},
tppubtype = {article}
}
Haruhiko Ito, Kazuhiro Yamamoto, Akifumi Takamizawa, Hiroyuki Kashiwagi, Takashi Yatsui
Deflecting, focusing, and funnelling atoms by near-field light Journal Article
In: Journal of Optics A: Pure and Applied Optics, vol. 8, no. 4, pp. S153-S160, 2006, (review article).
Abstract | Links | BibTeX | Tags: Atom, Near-field effect, Review
@article{Ito_2006,
title = {Deflecting, focusing, and funnelling atoms by near-field light},
author = {Haruhiko Ito and Kazuhiro Yamamoto and Akifumi Takamizawa and Hiroyuki Kashiwagi and Takashi Yatsui},
doi = {10.1088/1464-4258/8/4/s16},
year = {2006},
date = {2006-03-01},
journal = {Journal of Optics A: Pure and Applied Optics},
volume = {8},
number = {4},
pages = {S153-S160},
publisher = {IOP Publishing},
abstract = {We describe atom deflection with a slit-type deflector as an elemental
technique of precise atom control using near-field light. In the demonstration
experiments, cold Rb atoms deflected by repulsive near-field light induced in a
200 nm-wide slit are detected by means of two-step photoionization. Then, we
consider a near-field-light lens of atomic de Broglie waves by developing the
atom deflector. The feasibility of nanofocusing is shown by numerical analyses
with Fourier atom optics. Finally, we describe atom funnels with evanescent
light to generate a cold atomic beam required for atom manipulation using
nanometric near-field light. The flux intensity of cold Rb atoms outputted from a
240 µm outlet is estimated
to be 7.5 × 107 atom cm−2 s−1 at a blue
detuning of 1.2 GHz. In order to increase the flux intensity to
1012 atom cm−2 s−1, we develop a Si-made funnel with a micron-sized outlet.},
note = {review article},
keywords = {Atom, Near-field effect, Review},
pubstate = {published},
tppubtype = {article}
}
technique of precise atom control using near-field light. In the demonstration
experiments, cold Rb atoms deflected by repulsive near-field light induced in a
200 nm-wide slit are detected by means of two-step photoionization. Then, we
consider a near-field-light lens of atomic de Broglie waves by developing the
atom deflector. The feasibility of nanofocusing is shown by numerical analyses
with Fourier atom optics. Finally, we describe atom funnels with evanescent
light to generate a cold atomic beam required for atom manipulation using
nanometric near-field light. The flux intensity of cold Rb atoms outputted from a
240 µm outlet is estimated
to be 7.5 × 107 atom cm−2 s−1 at a blue
detuning of 1.2 GHz. In order to increase the flux intensity to
1012 atom cm−2 s−1, we develop a Si-made funnel with a micron-sized outlet.
Eue-Soon Jang, Jun Young Bae, Jinkyoung Yoo, Won Il Park, Dong-Wook Kim, Gyu-Chul Yi, Takashi Yatsui, Motoichi Ohtsu
Quantum confinement effect in ZnO/Mg0.2Zn0.8O multishell nanorod heterostructures Journal Article
In: Applied Physics Letters, vol. 88, no. 2, pp. 023102, 2006.
Abstract | Links | BibTeX | Tags: MQW, Near-field spectroscopy, ZnO
@article{doi:10.1063/1.2162695,
title = {Quantum confinement effect in ZnO/Mg0.2Zn0.8O multishell nanorod heterostructures},
author = {Eue-Soon Jang and Jun Young Bae and Jinkyoung Yoo and Won Il Park and Dong-Wook Kim and Gyu-Chul Yi and Takashi Yatsui and Motoichi Ohtsu},
doi = {10.1063/1.2162695},
year = {2006},
date = {2006-01-01},
urldate = {2006-01-01},
journal = {Applied Physics Letters},
volume = {88},
number = {2},
pages = {023102},
abstract = {We report on photoluminescence measurements of Mg0.2Zn0.8O/ZnO/Mg0.2Zn0.8O multishell layers on ZnO core nanorods. Dominant excitonic emissions in the photoluminescence spectra show a blueshift depending on the ZnO shell layer thickness attributed to the quantum confinement effect in the nanorod heterostructure radial direction. Furthermore, near-field scanning optical microscopy clearly shows sharp photoluminescence peaks from the individual nanorod quantum structures, corresponding to subband levels.},
keywords = {MQW, Near-field spectroscopy, ZnO},
pubstate = {published},
tppubtype = {article}
}
2005
Takashi Yatsui, Wataru Nomura, Motoichi Ohtsu
Self-Assembly of Size- and Position-Controlled Ultralong Nanodot Chains using Near-Field Optical Desorption Journal Article
In: Nano Letters, vol. 5, no. 12, pp. 2548-2551, 2005, (PMID: 16351213).
Abstract | Links | BibTeX | Tags: First, Nanophotonic fabrication, Plasmon, Selected, Self-assembly
@article{doi:10.1021/nl051898z,
title = {Self-Assembly of Size- and Position-Controlled Ultralong Nanodot Chains using Near-Field Optical Desorption},
author = {Takashi Yatsui and Wataru Nomura and Motoichi Ohtsu},
doi = {10.1021/nl051898z},
year = {2005},
date = {2005-12-01},
journal = {Nano Letters},
volume = {5},
number = {12},
pages = {2548-2551},
abstract = {We report the self-assembly of a size- and position-controlled ultralong nanodot chain using a novel effect of near-field optical desorption. A sub-100-nm dot chain with a deviation of 5 nm forms at a size based on plasmon resonance, depending on the photon energy; the resulting structure forms a high-transmission-efficiency nanoscale waveguide. Using this method with simple lithographically patterned substrates allows one to increase the throughput of the production of nanoscale structures dramatically at all scales.},
note = {PMID: 16351213},
keywords = {First, Nanophotonic fabrication, Plasmon, Selected, Self-assembly},
pubstate = {published},
tppubtype = {article}
}
Makoto Naruse, Takashi Yatsui, Wataru Nomura, Nobuaki Hirose, Motoichi Ohtsu
Hierarchy in optical near-fields and its application to memory retrieval Journal Article
In: Optics Express, vol. 13, no. 23, pp. 9265-9271, 2005.
Abstract | Links | BibTeX | Tags: Near-field effect
@article{Naruse:05,
title = {Hierarchy in optical near-fields and its application to memory retrieval},
author = {Makoto Naruse and Takashi Yatsui and Wataru Nomura and Nobuaki Hirose and Motoichi Ohtsu},
doi = {10.1364/OPEX.13.009265},
year = {2005},
date = {2005-11-01},
urldate = {2005-11-01},
journal = {Optics Express},
volume = {13},
number = {23},
pages = {9265-9271},
publisher = {OSA},
abstract = {Optical near-field interactions exhibit different behavior at different scales, which we term scale-dependent physical hierarchy. Using the intrinsic logical hierarchy of information and a simple digital coding scheme, scale-dependent optical memory accesses are associated with different levels of the information hierarchy. The basic principle is demonstrated by finite-different time-domain simulations and experiments using metal nanoparticles.},
keywords = {Near-field effect},
pubstate = {published},
tppubtype = {article}
}
Takashi Yatsui, Wataru Nomura, Motoichi Ohtsu
Size-, Position-, and Separation-Controlled One-Dimensional Alignment of Nanoparticles Using an Optical Near Field Journal Article
In: IEICE TRANSACTIONS on Electronics, vol. E88-C, no. 9, pp. 1798-1802, 2005.
Abstract | Links | BibTeX | Tags: First, Nanophotonic fabrication, Self-assembly
@article{2005IEICE,
title = {Size-, Position-, and Separation-Controlled One-Dimensional Alignment of Nanoparticles Using an Optical Near Field},
author = {Takashi Yatsui and Wataru Nomura and Motoichi Ohtsu},
doi = {10.1093/ietele/e88-c.9.1798},
year = {2005},
date = {2005-09-01},
journal = {IEICE TRANSACTIONS on Electronics},
volume = {E88-C},
number = {9},
pages = {1798-1802},
publisher = {IEICE},
abstract = {Particles several tens of nanometers in size were aligned in the desired positions in a controlled manner by using capillary force interaction and suspension flow. Latex beads 40-nm in diameter were aligned linearly around a 10-um-hole template fabricated by lithography. Further control of their position and separation was realized using colloidal gold nanoparticles by controlling the particle-substrate and particle-particle interactions using an optical near field generated on the edge of a Si wedge, in which the separation of the colloidal gold nanoparticles was controlled by the direction of polarization.},
keywords = {First, Nanophotonic fabrication, Self-assembly},
pubstate = {published},
tppubtype = {article}
}
Jungshik Lim, Takashi Yatsui, Motoichi Ohtsu
In: IEICE TRANSACTIONS on Electronics, vol. E88-C, no. 9, pp. 1832-1835, 2005.
Abstract | Links | BibTeX | Tags: Nanophotonic fabrication, Size-dependent resonance
@article{2005limIEICE,
title = {Observation of Size-Dependent Resonance of Near-Field Coupling between a Deposited Zn Dot and the Probe Apex during Near-Field Optical Chemical Vapor Deposition},
author = {Jungshik Lim and Takashi Yatsui and Motoichi Ohtsu},
doi = {10.1093/ietele/e88-c.9.1832},
year = {2005},
date = {2005-09-01},
journal = {IEICE TRANSACTIONS on Electronics},
volume = {E88-C},
number = {9},
pages = {1832-1835},
publisher = {IEICE},
abstract = {We investigated the initial stage of Zn dot growth using near-field optical chemical vapor deposition. The dependence of the rate of Zn dot deposition on dot size revealed that the deposition rate was maximal when the dot grew to a size equivalent to the probe apex diameter. Such observed size-dependent resonance was in good agreement with theoretical results for dipole-dipole coupling with a Forster field between the deposited Zn dot and the probe apex.},
keywords = {Nanophotonic fabrication, Size-dependent resonance},
pubstate = {published},
tppubtype = {article}
}
Takashi Yatsui, Motoichi Ohtsu, Jinkyoung Yoo, Sung Jin An, Gyu-Chul Yi
Near-field measurement of spectral anisotropy and optical absorption of isolated ZnO nanorod single-quantum-well structures Journal Article
In: Applied Physics Letters, vol. 87, no. 3, pp. 033101, 2005.
Abstract | Links | BibTeX | Tags: First, Near-field spectroscopy, QW, ZnO
@article{doi:10.1063/1.1990247,
title = {Near-field measurement of spectral anisotropy and optical absorption of isolated ZnO nanorod single-quantum-well structures},
author = {Takashi Yatsui and Motoichi Ohtsu and Jinkyoung Yoo and Sung Jin An and Gyu-Chul Yi},
doi = {10.1063/1.1990247},
year = {2005},
date = {2005-07-01},
urldate = {2005-07-01},
journal = {Applied Physics Letters},
volume = {87},
number = {3},
pages = {033101},
abstract = {We report low-temperature near-field spectroscopy of isolated ZnO∕ZnMgO single-quantum-well structures (SQWs) on the end of ZnO nanorod to define their potential for nanophotonics. First, absorption spectra of isolated ZnO∕ZnMgO nanorod SQWs with the Stokes shift as small as 3meV and very sharp photoluminescent peaks indicate that the nanorod SQWs are of very high optical quality. Furthermore, we performed polarization spectroscopy of isolated ZnO SQWs, and observed valence-band anisotropy of ZnO SQWs in photoluminescence spectra directly. Since the exciton in a quantum structure is an ideal two-level system with long coherence times, our results provide criteria for designing nanophotonic devices.},
keywords = {First, Near-field spectroscopy, QW, ZnO},
pubstate = {published},
tppubtype = {article}
}
Wataru Nomura, Motoichi Ohtsu, Takashi Yatsui
Nanodot coupler with a surface plasmon polariton condenser for optical far/near-field conversion Journal Article
In: Applied Physics Letters, vol. 86, no. 18, pp. 181108, 2005.
Abstract | Links | BibTeX | Tags: Plasmon, Selected
@article{doi:10.1063/1.1920419,
title = {Nanodot coupler with a surface plasmon polariton condenser for optical far/near-field conversion},
author = {Wataru Nomura and Motoichi Ohtsu and Takashi Yatsui},
doi = {10.1063/1.1920419},
year = {2005},
date = {2005-05-01},
urldate = {2005-05-01},
journal = {Applied Physics Letters},
volume = {86},
number = {18},
pages = {181108},
abstract = {To transmit an optical signal to a nanophotonic device, a nanodot coupler was fabricated from a linear array of closely spaced metallic nanoparticles. To increase the optical far- to near-field conversion efficiency for transmission, a surface plasmon polariton (SPP) condenser was also fabricated from hemispherical metallic nanoparticles so that it worked as a “phased array”. The SPP was focused with a spot size as small as 400 nm at λ=785nm. When the focused SPP was incident into the nanodot coupler, its transmission length through the nanodot coupler was confirmed to be 4.0 μm, which is three times longer than that of a metallic core waveguide owing to the efficient near-field coupling between the localized surface plasmon of neighboring nanoparticles. Furthermore, the transmission length through a zigzag-shaped nanodot coupler was as long as that through a linear one.},
keywords = {Plasmon, Selected},
pubstate = {published},
tppubtype = {article}
}
Kiyoshi Yatsui, Michiharu Gunji, Sung-Chae Yang, Hisayuki Suematsu, Weihua Jiang, Takashi Yatsui, Motoichi Ohtsu
Blue Light Emission from Ultrafine Nanosized Powder of Silicon Produced by Intense Pulsed Ion-Beam Evaporation Journal Article
In: Japanese Journal of Applied Physics, vol. 44, no. 2, pp. L92-L94, 2005.
Abstract | Links | BibTeX | Tags: Si
@article{Yatsui_2004,
title = {Blue Light Emission from Ultrafine Nanosized Powder of Silicon Produced by Intense Pulsed Ion-Beam Evaporation},
author = {Kiyoshi Yatsui and Michiharu Gunji and Sung-Chae Yang and Hisayuki Suematsu and Weihua Jiang and Takashi Yatsui and Motoichi Ohtsu},
doi = {10.1143/jjap.44.l92},
year = {2005},
date = {2005-01-01},
journal = {Japanese Journal of Applied Physics},
volume = {44},
number = {2},
pages = {L92-L94},
publisher = {IOP Publishing},
abstract = {Blue light emission has been observed from ultrafine nanosized powder of silicon, which was synthesized by rapid cooling of high-density ablation plasma produced by intense pulsed light-ion beam interaction with a silicon target, called pulsed ion-beam evaporation. The emission appears from the powder without heat treatment after being synthesized. Furthermore, the emission is found to be very stable; neither red- nor blue-shift is observed. In fact, the spectrum from the powder four months after the synthesis is the same as those from as-synthesized powder. The rapid heat cooling inherent to ion-beam evaporation seems to be essential for emission.},
keywords = {Si},
pubstate = {published},
tppubtype = {article}
}
2004
Shunsuke Yamazaki, Takashi Yatsui, Motoichi Ohtsu, Taw-Won Kim, Hiroshi Fujioka
Room-temperature synthesis of ultraviolet-emitting nanocrystalline GaN films using photochemical vapor deposition Journal Article
In: Applied Physics Letters, vol. 85, no. 15, pp. 3059-3061, 2004.
Abstract | Links | BibTeX | Tags: GaN
@article{doi:10.1063/1.1806271,
title = {Room-temperature synthesis of ultraviolet-emitting nanocrystalline GaN films using photochemical vapor deposition},
author = {Shunsuke Yamazaki and Takashi Yatsui and Motoichi Ohtsu and Taw-Won Kim and Hiroshi Fujioka},
doi = {10.1063/1.1806271},
year = {2004},
date = {2004-10-01},
journal = {Applied Physics Letters},
volume = {85},
number = {15},
pages = {3059-3061},
abstract = {We fabricated UV-emitting nanocrystalline gallium nitride (GaN) films at room temperature using photochemical vapor deposition (PCVD). For the samples synthesized at room temperature with V/III ratios exceeding 5.0×10^4, strong photoluminescence peaks at 3.365 and 3.310eV, which can be ascribed to transitions in a mixed phase of cubic and hexagonal GaN, were observed at 5K. A UV emission spectrum with a full width at half-maximum of 100meV was observed, even at room temperature. In addition, x-ray photoelectron spectroscopy measurement revealed that the film deposited by PCVD at room temperature was well nitridized.},
keywords = {GaN},
pubstate = {published},
tppubtype = {article}
}
Takashi Yatsui, Jungshik Lim, Motoichi Ohtsu, Sung Jin An, Gyu-Chul Yi
In: Applied Physics Letters, vol. 85, no. 5, pp. 727-729, 2004.
Abstract | Links | BibTeX | Tags: First, nanorod, Near-field spectroscopy, QW, ZnO
@article{doi:10.1063/1.1776338,
title = {Evaluation of the discrete energy levels of individual ZnO nanorodsingle-quantum-well structures using near-field ultraviolet photoluminescence spectroscopy},
author = {Takashi Yatsui and Jungshik Lim and Motoichi Ohtsu and Sung Jin An and Gyu-Chul Yi},
doi = {10.1063/1.1776338},
year = {2004},
date = {2004-08-01},
urldate = {2004-08-01},
journal = {Applied Physics Letters},
volume = {85},
number = {5},
pages = {727-729},
abstract = {Spatially and spectrally resolved photoluminescence imaging of individual ZnO∕ZnMgO nanorod single-quantum-well structures (SQWs) with a spatial resolution of 55nm was performed using the optical near-field technique with a metallized UV fiber probe. Using excitation power density-dependent photoluminescence spectra of a ZnO∕ZnMgO SQW nanorod, we observed the discrete energy levels in a ZnO quantum-well layer.},
keywords = {First, nanorod, Near-field spectroscopy, QW, ZnO},
pubstate = {published},
tppubtype = {article}
}
2003
Takashi Yatsui, Akira Takubo, Jungshik Lim, Wataru Nomura, Motonobu Kourogi, Motoichi Ohtsu
Regulating the size and position of deposited Zn nanoparticles by optical near-field desorption using size-dependent resonance Journal Article
In: Applied Physics Letters, vol. 83, no. 9, pp. 1716-1718, 2003.
Abstract | Links | BibTeX | Tags: First, Self-assembly, Size-dependent resonance
@article{doi:10.1063/1.1606883,
title = {Regulating the size and position of deposited Zn nanoparticles by optical near-field desorption using size-dependent resonance},
author = {Takashi Yatsui and Akira Takubo and Jungshik Lim and Wataru Nomura and Motonobu Kourogi and Motoichi Ohtsu},
doi = {10.1063/1.1606883},
year = {2003},
date = {2003-09-01},
journal = {Applied Physics Letters},
volume = {83},
number = {9},
pages = {1716-1718},
abstract = {We report that optical near-field desorption can dramatically regulate the growth of Zn nanoparticles during optical chemical vapor deposition. The trade off between the deposition due to 3.81 eV optical near-field light and desorption due to 2.54 eV optical near-field light allowed the fabrication of a single 15 nm Zn dot, while regulating its size and position.},
keywords = {First, Self-assembly, Size-dependent resonance},
pubstate = {published},
tppubtype = {article}
}
Tae-Won Kim, Tadashi Kawazoe, Shunsuke Yamazaki, Jungshik Lim, Takashi Yatsui, Motoichi Ohtsu
Room temperature ultraviolet emission from ZnO nanocrystallites fabricated by the low temperature oxidation of metallic Zn precursors Journal Article
In: Solid State Communications, vol. 127, no. 1, pp. 21 - 24, 2003, ISSN: 0038-1098.
Abstract | Links | BibTeX | Tags: ZnO
@article{KIM200321,
title = {Room temperature ultraviolet emission from ZnO nanocrystallites fabricated by the low temperature oxidation of metallic Zn precursors},
author = {Tae-Won Kim and Tadashi Kawazoe and Shunsuke Yamazaki and Jungshik Lim and Takashi Yatsui and Motoichi Ohtsu},
doi = {10.1016/S0038-1098(03)00346-6},
issn = {0038-1098},
year = {2003},
date = {2003-04-01},
journal = {Solid State Communications},
volume = {127},
number = {1},
pages = {21 - 24},
abstract = {We have successfully fabricated ZnO nanocrystallites emitting strong ultraviolet radiation at room temperature via the simple thermal oxidation of metallic Zn precursors at 380 °C. X-ray diffraction measurements showed only the diffraction peak from ZnO, revealing that metallic Zn precursors were successfully oxidized even at the low temperature of 380 °C. The mean size of the ZnO nanocrystallites determined using Scherrer's formula was ca. 30 nm. Room temperature photoluminescence measurements using a cw He–Cd laser (λ=325nm) showed a strong emission peak at 3.27eV, which was ascribed to free excition recombination. These results suggest that sufficient oxygen can diffuse into the metallic Zn precursors, even at temperatures as low as 380 °C, to allow the fabrication of pure ZnO nanocrystallites.},
keywords = {ZnO},
pubstate = {published},
tppubtype = {article}
}
Kouki Totsuka, Haruhiko Ito, Kiichi Suzuki, Kazuhiro Yamamoto, Motoichi Ohtsu, Takashi Yatsui
A slit-type atom deflector with near-field light Journal Article
In: Applied Physics Letters, vol. 82, no. 10, pp. 1616-1618, 2003.
Abstract | Links | BibTeX | Tags: Atom
@article{doi:10.1063/1.1558222,
title = {A slit-type atom deflector with near-field light},
author = {Kouki Totsuka and Haruhiko Ito and Kiichi Suzuki and Kazuhiro Yamamoto and Motoichi Ohtsu and Takashi Yatsui},
doi = {10.1063/1.1558222},
year = {2003},
date = {2003-03-01},
journal = {Applied Physics Letters},
volume = {82},
number = {10},
pages = {1616-1618},
abstract = {We developed a near-field optical deflector for precise direction control of atomic motion using a dipole force. The blue-detuned, near-field light used to deflect atoms was generated near the edge of a 100-nm-wide slit and had a spatial distribution of 126 nm at a distance of 10 nm from the top edge. The deflection angle for a Rb atom was a function of light intensity, frequency detuning, and atomic velocity.},
keywords = {Atom},
pubstate = {published},
tppubtype = {article}
}
2002
Jungshik Lim, Tadashi Kawazoe, Takashi Yatsui, Motoichi Ohtsu
Fabrication of a Ferromagnetic-Coated Fiber Probe with a Double-Layer Structure Journal Article
In: IEICE TRANSACTIONS on Electronics, vol. E88-C, no. 12, pp. 1832-1835, 2002, ISSN: 0916-8516.
Abstract | Links | BibTeX | Tags: Ferromagnetic
@article{2002limIEICE,
title = {Fabrication of a Ferromagnetic-Coated Fiber Probe with a Double-Layer Structure},
author = {Jungshik Lim and Tadashi Kawazoe and Takashi Yatsui and Motoichi Ohtsu},
url = {https://search.ieice.org/bin/summary.php?id=e85-c_12_2077&category=C&year=2002&lang=E&abst=},
issn = {0916-8516},
year = {2002},
date = {2002-12-01},
journal = {IEICE TRANSACTIONS on Electronics},
volume = {E88-C},
number = {12},
pages = {1832-1835},
publisher = {IEICE},
abstract = {We fabricated the first Fe-coated fiber probe for magneto-optical applications. In order to improve the optical confinement capability, we used a double-layer structure, with a thin coating of Au. The double-layer structure consisted of 50-nm-thick Fe and 50-nm-thick Au. A probe-to-probe experiment confirmed that the fabricated fiber probe had an effective optical confinement capability for optical near-field measurement.},
keywords = {Ferromagnetic},
pubstate = {published},
tppubtype = {article}
}
Takashi Yatsui, Tadashi Kawazoe, Minoru Ueda, Yoh Yamamoto, Motonobu Kourogi, Motoichi Ohtsu
In: Applied Physics Letters, vol. 81, no. 19, pp. 3651-3653, 2002.
Abstract | Links | BibTeX | Tags: First, Near-field effect
@article{doi:10.1063/1.1520337,
title = {Fabrication of nanometric single zinc and zinc oxide dots by the selective photodissociation of adsorption-phase diethylzinc using a nonresonant optical near field},
author = {Takashi Yatsui and Tadashi Kawazoe and Minoru Ueda and Yoh Yamamoto and Motonobu Kourogi and Motoichi Ohtsu},
doi = {10.1063/1.1520337},
year = {2002},
date = {2002-11-01},
journal = {Applied Physics Letters},
volume = {81},
number = {19},
pages = {3651-3653},
abstract = {We demonstrated a deposition of nanometer-scale Zn dots using the selective photodissociation of adsorption-phase diethylzinc with a nonresonant optical near field, where the photon energy is lower than that of the absorption edge of gas-phase diethylzinc. We achieved nanometric prenucleation by dissociating diethylzinc molecules adsorbed on a substrate. Subsequent deposition was performed by dissociating the adsorbed molecules on the prenucleated Zn. The topographic image of the deposited Zn dot had a full width at half maximum (FWHM) of 25 nm. Furthermore, the photoluminescence intensity distribution from a single ZnO dot fabricated using laser annealing had a FWHM of 85 nm.},
keywords = {First, Near-field effect},
pubstate = {published},
tppubtype = {article}
}
Motoichi Ohtsu, Kiyoshi Kobayashi, Tadashi Kawazoe, Suguru Sangu, Takashi Yatsui
Nanophotonics: design, fabrication, and operation of nanometric devices using optical near fields Journal Article
In: IEEE Journal of Selected Topics in Quantum Electronics, vol. 8, no. 4, pp. 839-862, 2002, (review article).
Abstract | Links | BibTeX | Tags: Nanophotonic device, Nanophotonic fabrication, Review, Selected
@article{2008IEEEb,
title = {Nanophotonics: design, fabrication, and operation of nanometric devices using optical near fields},
author = {Motoichi Ohtsu and Kiyoshi Kobayashi and Tadashi Kawazoe and Suguru Sangu and Takashi Yatsui},
doi = {10.1109/JSTQE.2002.801738},
year = {2002},
date = {2002-07-01},
journal = {IEEE Journal of Selected Topics in Quantum Electronics},
volume = {8},
number = {4},
pages = {839-862},
publisher = {IEEE},
abstract = {This paper reviews progress in nanophotonics, a novel optical nanotechnology, utilizing local electromagnetic interactions between a few nanometric elements and an optical near field. A prototype of a nanophotonic integrated circuit (IC) is presented, in which the optical near field is used as a carrier to transmit a signal from one nanometric dot to another. Each section of this paper reviews theoretical and experimental studies carried out to assess the possibility of designing, fabricating, and operating each nanophotonic IC device. A key device, the nanophotonic switch, is proposed based on optical near-field energy transfer between quantum dots (QDs). The optical near-field interaction is expressed as the sum of the Yukawa function, and the oscillation period of the nutation of cubic CuCl QDs is estimated to be less than 100 ps. To guarantee one-directional (i.e., irreversible) energy transfer between two resonant levels of QDs, intrasublevel transitions due to phonon coupling are examined by considering a simple two-QD plus phonon heat bath system. As a result, the state-filling time is estimated as 22 ps for CuCl QDs. This time is almost independent of the temperature in the Born-Markov approximation. Using cubic CuCl QDs in a NaCl matrix as a test sample, the optical near-field energy transfer was experimentally verified by near-field optical spectroscopy with a spatial resolution smaller than 50 nm in the near-UV region at 15 K. This transfer occurs from the lowest state of excitons in 4.6-nm QDs to the first dipole-forbidden excited state of excitons in 6.3-nm QDs. To fabricate nanophotonic devices and ICs, chemical vapor deposition using an optical near field is proposed; this is sufficiently precise in controlling the size and position of the deposited material. A novel deposition scheme under nonresonant conditions is also demonstrated and its origin is discussed. In order to confirm the possibility of using a nanometric ZnO dot as a light emitter in a nanophotonic IC, spatially and spectrally resolved photoluminescence imaging of individual ZnO nanocrystallites was carried out with a spatial resolution as high as 55 nm, using a UV fiber probe, and the spectral shift due to the quantum size effect was found. To connect the nanophotonic IC to external photonic devices, a nanometer-scale waveguide was developed using a metal-coated silicon wedge structure. Illumination (wavelength: 830 nm) of the metal-coated silicon wedge (width: 150 nm) excites a TM plasmon mode with a beam width of 150 nm and propagation length of 2.5 /spl mu/m. A key device for nanophotonics, an optical near-field probe with an extremely high throughput, was developed by introducing a pyramidal silicon structure with localized surface plasmon resonance at the metallized probe tip. A throughput as high as 2.3% was achieved. Finally, as an application of nanophotonics to, a high-density, high-speed optical memory system, a novel contact slider with a pyramidal silicon probe array was developed. This slider was used for phase-change recording and reading, and a mark length as short as 110 nm was demonstrated.},
note = {review article},
keywords = {Nanophotonic device, Nanophotonic fabrication, Review, Selected},
pubstate = {published},
tppubtype = {article}
}
Takashi Yatsui, Kazutaka Itsumi, Motonobu Kourogi, Motoichi Ohtsu
Metallized pyramidal silicon probe with extremely high throughput and resolution capability for optical near-field technology Journal Article
In: Applied Physics Letters, vol. 80, no. 13, pp. 2257-2259, 2002.
Abstract | Links | BibTeX | Tags: First, near-field optical recording, Plasmon
@article{doi:10.1063/1.1465520,
title = {Metallized pyramidal silicon probe with extremely high throughput and resolution capability for optical near-field technology},
author = {Takashi Yatsui and Kazutaka Itsumi and Motonobu Kourogi and Motoichi Ohtsu},
doi = {10.1063/1.1465520},
year = {2002},
date = {2002-04-01},
journal = {Applied Physics Letters},
volume = {80},
number = {13},
pages = {2257-2259},
abstract = {An optical near-field probe with extremely high throughput and resolution capability was fabricated with a metallized pyramidal silicon structure. Using a finite-difference time-domain method, we found the tip parameters that are required for localized surface plasmon resonance at the probe tip. The optical near-field energy distribution on the metallized pyramidal silicon probe was observed by scanning a fiber probe that had an aperture diameter of 50 nm. The spatial distribution profile observed was in good agreement with the numerical results. The throughput and spot size were determined to be 2.3% and 85 nm, respectively.},
keywords = {First, near-field optical recording, Plasmon},
pubstate = {published},
tppubtype = {article}
}
Takashi Yatsui, Tadashi Kawazoe, Takashi Shimizu, Yoh Yamamoto, Minoru Ueda, Motonobu Kourogi, Motoichi Ohtsu, Geun-Hyoung Lee
Observation of size-dependent features in the photoluminescence of zinc oxide nanocrystallites by near-field ultraviolet spectroscopy Journal Article
In: Applied Physics Letters, vol. 80, no. 8, pp. 1444-1446, 2002.
Abstract | Links | BibTeX | Tags: First, Near-field spectroscopy, ZnO
@article{doi:10.1063/1.1453487,
title = {Observation of size-dependent features in the photoluminescence of zinc oxide nanocrystallites by near-field ultraviolet spectroscopy},
author = {Takashi Yatsui and Tadashi Kawazoe and Takashi Shimizu and Yoh Yamamoto and Minoru Ueda and Motonobu Kourogi and Motoichi Ohtsu and Geun-Hyoung Lee},
doi = {10.1063/1.1453487},
year = {2002},
date = {2002-01-01},
journal = {Applied Physics Letters},
volume = {80},
number = {8},
pages = {1444-1446},
abstract = {The optical properties of single zinc oxide (ZnO) nanocrystallites were investigated at room temperature by extending the optical near-field technique to the UV region. Using a UV fiber probe with a subwavelength aperture, we performed spatially- and spectrally-resolved photoluminescence (PL) imaging of individual ZnO nanocrystallites with a spatial resolution of 55 nm. Furthermore, decreasing the spot size increased the intensities of higher-energy components of the PL spectrum due to the quantum size effect.},
keywords = {First, Near-field spectroscopy, ZnO},
pubstate = {published},
tppubtype = {article}
}
2001
Takashi Yatsui, Motonobu Kourogi, Motoichi Ohtsu
Plasmon waveguide for optical far/near-field conversion Journal Article
In: Applied Physics Letters, vol. 79, no. 27, pp. 4583-4585, 2001.
Abstract | Links | BibTeX | Tags: First, Plasmon, Selected
@article{doi:10.1063/1.1428405,
title = {Plasmon waveguide for optical far/near-field conversion},
author = {Takashi Yatsui and Motonobu Kourogi and Motoichi Ohtsu},
doi = {10.1063/1.1428405},
year = {2001},
date = {2001-12-01},
journal = {Applied Physics Letters},
volume = {79},
number = {27},
pages = {4583-4585},
abstract = {A plasmon waveguide was designed and fabricated using a metal-coated silicon wedge structure that converts propagating far-field light to the near field. Illumination (λ=830 nm) of the waveguide (plateau width 150 nm) caused transverse magnetic plasmon-mode excitation. Use of a near-field microscope allowed us to determine its beam width and propagation length as 150 nm and 2.5 μm, respectively.},
keywords = {First, Plasmon, Selected},
pubstate = {published},
tppubtype = {article}
}
Takashi Yatsui, Takashi Shimizu, Yoh Yamamoto, Motonobu Kourogi, Motoichi Ohtsu, Geun-Hyoung Lee
Near-field ultraviolet photoluminescence spectroscopy for evaluating the crystallinity of polycrystalline zinc oxide Journal Article
In: Applied Physics Letters, vol. 79, no. 15, pp. 2369-2371, 2001.
Abstract | Links | BibTeX | Tags: First, Near-field spectroscopy, ZnO
@article{doi:10.1063/1.1410357,
title = {Near-field ultraviolet photoluminescence spectroscopy for evaluating the crystallinity of polycrystalline zinc oxide},
author = {Takashi Yatsui and Takashi Shimizu and Yoh Yamamoto and Motonobu Kourogi and Motoichi Ohtsu and Geun-Hyoung Lee},
doi = {10.1063/1.1410357},
year = {2001},
date = {2001-10-01},
journal = {Applied Physics Letters},
volume = {79},
number = {15},
pages = {2369-2371},
abstract = {By extending the optical near-field technique to the ultraviolet region, a two-dimensional evaluation of the optical properties and crystallinity of polycrystalline zinc oxide (ZnO) was carried out at room temperature. Using an ultraviolet fiber probe with an aperture diameter of 80 nm, we obtained spatially resolved photoluminescence spectra from individual ZnO nanocrystallites; the emission intensity depended on the topography and on crystal orientation.},
keywords = {First, Near-field spectroscopy, ZnO},
pubstate = {published},
tppubtype = {article}
}
2000
Takashi Yatsui, Motonobu Kourogi, Kazuo Tsutsui, Motoichi Ohtsu, Jun-ichi Takahashi
High-density-speed optical near-field recording--reading with a pyramidal silicon probe on a contact slider Journal Article
In: Optics Letters, vol. 25, no. 17, pp. 1279-1281, 2000.
Abstract | Links | BibTeX | Tags: First, near-field optical recording, Plasmon
@article{Yatsui:00,
title = {High-density-speed optical near-field recording--reading with a pyramidal silicon probe on a contact slider},
author = {Takashi Yatsui and Motonobu Kourogi and Kazuo Tsutsui and Motoichi Ohtsu and Jun-ichi Takahashi},
doi = {10.1364/OL.25.001279},
year = {2000},
date = {2000-09-01},
journal = {Optics Letters},
volume = {25},
number = {17},
pages = {1279-1281},
publisher = {OSA},
abstract = {We demonstrate high-density-speed phase-change recording-reading by use of a pyramidal silicon structure. The contact slider, which has a pyramidal silicon probe array with height dispersion of less than 10 nm, is fabricated by use of a silicon-on-insulator wafer. By illumination with a laser beam λ=830 nm of one element of the probe array, we find the shortest phase-change mark length and the carrier-to-noise ratio to be 110 nm and 10 dB, respectively, corresponding to a data transmission rate of 2.0 MHz. This rate can be increased to 200 MHz by use of all elements of the probe array.},
keywords = {First, near-field optical recording, Plasmon},
pubstate = {published},
tppubtype = {article}
}
1999
Myung Bok Lee, Motonobu Kourogi, Takashi Yatsui, Kazuo Tsutsui, Nobufumi Atoda, Motoichi Ohtsu
Silicon planar-apertured probe array for high-density near-field optical storage Journal Article
In: Applied Optics, vol. 38, no. 16, pp. 3566-3571, 1999.
Abstract | Links | BibTeX | Tags: near-field optical recording
@article{Lee:99,
title = {Silicon planar-apertured probe array for high-density near-field optical storage},
author = {Myung Bok Lee and Motonobu Kourogi and Takashi Yatsui and Kazuo Tsutsui and Nobufumi Atoda and Motoichi Ohtsu},
doi = {10.1364/AO.38.003566},
year = {1999},
date = {1999-06-01},
journal = {Applied Optics},
volume = {38},
number = {16},
pages = {3566-3571},
publisher = {OSA},
abstract = {We propose a novel, to our knowledge, silicon planar-aperturedprobe array as an optical head for high-density near-field opticalstorage. In comparison with a conventional fiber probe employed fornear-field optical storage the apertured probe array has a higherreadout data-transmission rate and better mechanical durability. Aprobe array with an aperture size of 100 nm was fabricated by use ofphotolithography and wet etching of a siliconwafer. Subwavelength-readout capability was demonstrated by use ofone aperture of the probe array. Furthermore, we achieved a 16times increase in the light-transmission efficiency of the probe arrayby installing glass-sphere microlenses on each aperture. Theincrease was confirmed by measurement of the near-field opticalintensity.},
keywords = {near-field optical recording},
pubstate = {published},
tppubtype = {article}
}
1998
Takuya Matsumoto, Tutomu Ichimura, Takashi Yatsui, Motonobu Kourogi, Toshiharu Saiki, Motoichi Ohtsu
Fabrication of a Near-Field Optical Fiber Probe with a Nanometric Metallized Protrusion Journal Article
In: Optical Review, vol. 5, no. 6, pp. 369-373, 1998.
Abstract | Links | BibTeX | Tags: Plasmon
@article{1998matsumoto,
title = {Fabrication of a Near-Field Optical Fiber Probe with a Nanometric Metallized Protrusion},
author = {Takuya Matsumoto and Tutomu Ichimura and Takashi Yatsui and Motonobu Kourogi and Toshiharu Saiki and Motoichi Ohtsu},
doi = {10.1007/s10043-998-0369-1},
year = {1998},
date = {1998-12-01},
journal = {Optical Review},
volume = {5},
number = {6},
pages = {369-373},
publisher = {Springer Nature},
abstract = {We have developed a novel probe with a nanometric metallized protrusion extending through a subwavelength aperture to increase optical near-field excitation and collection efficiencies. The apex diameter of the fabricated metallized protrusion was 35 nm. The Intensity distribution of the optical near-field at the apex of the probe was measured by scanning another probe across the apex, and it was observed that strong optical near-field was generated at the apex of the metallized protrusion. The width of the intensity distribution was 150 nm including instrumental resolution. Probes with spherical and ellipsoidal metallized protrusion were also fabricated, by which enhancement of the optical near-field is expected due to localized plasmon excitation.},
keywords = {Plasmon},
pubstate = {published},
tppubtype = {article}
}
Takashi Yatsui, Motonobu Kourogi, Motoichi Ohtsu
Increasing throughput of a near-field optical fiber probe over 1000 times by the use of a triple-tapered structure Journal Article
In: Applied Physics Letters, vol. 73, no. 15, pp. 2090-2092, 1998.
Abstract | Links | BibTeX | Tags: First, Plasmon, Selected
@article{doi:10.1063/1.122387,
title = {Increasing throughput of a near-field optical fiber probe over 1000 times by the use of a triple-tapered structure},
author = {Takashi Yatsui and Motonobu Kourogi and Motoichi Ohtsu},
doi = {10.1063/1.122387},
year = {1998},
date = {1998-10-01},
journal = {Applied Physics Letters},
volume = {73},
number = {15},
pages = {2090-2092},
abstract = {We fabricated a new probe with extremely high throughput introducing a triple-tapered structure to reduce the loss in a tapered core, to focus the light, and to excite effectively the HE11 mode. A focused ion beam and selective chemical etching were used for fabrication. Over a 1000-fold increase in the throughput of the triple-tapered probe with the aperture diameter D<100 nm was realized in comparison with the conventional single-tapered probe. Furthermore, due to the third taper with a small cone angle, the localized optical near field on the triple-tapered apertured probe with D=60 nm has been confirmed.},
keywords = {First, Plasmon, Selected},
pubstate = {published},
tppubtype = {article}
}
1997
Takashi Yatsui, Motonobu Kourogi, Motoichi Ohtsu
Highly efficient excitation of optical near-field on an apertured fiber probe with an asymmetric structure Journal Article
In: Applied Physics Letters, vol. 71, no. 13, pp. 1756-1758, 1997.
Abstract | Links | BibTeX | Tags: First, Plasmon
@article{doi:10.1063/1.119390,
title = {Highly efficient excitation of optical near-field on an apertured fiber probe with an asymmetric structure},
author = {Takashi Yatsui and Motonobu Kourogi and Motoichi Ohtsu},
doi = {10.1063/1.119390},
year = {1997},
date = {1997-09-01},
journal = {Applied Physics Letters},
volume = {71},
number = {13},
pages = {1756-1758},
abstract = {We propose and demonstrate a novel method to enhance the near-field optical intensity on the apertured probe with its foot removed asymmetrically by using a focused ion beam. The spatial distribution of the near-field optical intensity on the asymmetric probe was observed by scanning another sharpened symmetric probe over the aperture. The observed spatial distribution profile was in good agreement with a numerical result corresponding to the HE11 mode. Furthermore, compared with the symmetric apertured probe, a 10 times enhancement of the near-field optical intensity on the asymmetric apertured probe was observed.},
keywords = {First, Plasmon},
pubstate = {published},
tppubtype = {article}
}