start-ver=1.4
cd-journal=joma
no-vol=33
cd-vols=
no-issue=8
article-no=
start-page=18515
end-page=18529
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2025
dt-pub=20250418
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=Demonstration of enhanced Raman scattering in high-Q silicon nanocavities operating below the silicon band-gap wavelength
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=We experimentally determined the quality factor (Q) and the intensity of the Raman scattered light for different silicon photonic-crystal nanocavities operating at wavelengths shorter than the silicon band-gap wavelength. Despite the relatively large absorption of silicon in this wavelength region, we observed Q values greater than 10,000 for cavities with a resonance wavelength of 1.05 mu m, and Q values greater than 30,000 for cavities with a resonance wavelength of 1.10 mu m. Additionally, we measured the Raman scattering spectra of cavities with resonance wavelengths of 1.10 mu m and 1.21 mu m. On average, the generation efficiency of the Raman scattered light in a 1.10-mu m nanocavity is 6.5 times higher than that in a 1.21-mu m nanocavity. These findings suggest that silicon nanocavities operating below the silicon band-gap wavelength could be useful in the development of silicon-based light sources.
en-copyright=
kn-copyright=

en-aut-name=ShimomuraYu
en-aut-sei=Shimomura
en-aut-mei=Yu
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=1
ORCID=

en-aut-name=AsanoTakashi
en-aut-sei=Asano
en-aut-mei=Takashi
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=2
ORCID=

en-aut-name=IshiharaAyumi
en-aut-sei=Ishihara
en-aut-mei=Ayumi
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=3
ORCID=

en-aut-name=NodaSusumu
en-aut-sei=Noda
en-aut-mei=Susumu
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=4
ORCID=

en-aut-name=TakahashiYasushi
en-aut-sei=Takahashi
en-aut-mei=Yasushi
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=5
ORCID=

affil-num=1
en-affil=Department of Physics and Electronics, Osaka Metropolitan University
kn-affil=

affil-num=2
en-affil=Department of Electronic Science and Engineering, Kyoto University
kn-affil=

affil-num=3
en-affil=Department of Physics and Electronics, Osaka Metropolitan University
kn-affil=

affil-num=4
en-affil=Department of Electronic Science and Engineering, Kyoto University
kn-affil=

affil-num=5
en-affil=Graduate School of Environmental, Life, Natural Science and Technology, Okayama University
kn-affil=
END

start-ver=1.4
cd-journal=joma
no-vol=31
cd-vols=
no-issue=23
article-no=
start-page=38529
end-page=38539
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2023
dt-pub=20231106
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=Optical multi-context scrubbing operation on a redundant system
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=This paper presents a proposal of the world-first optical multi-context scrubbing operation on a redundant system that can maintain the state of a sequential circuit and the operation continuously without any interruption on a radiation-hardened optically reconfigurable gate array even after a permanent failure suddenly happens on the sequential circuit or a flip-flop by radiation. Up to now, a high-speed optical scrubbing operation has been demonstrated on a radiation-hardened optically reconfigurable gate array. In addition, a multi-context scrubbing operation based on the high-speed optical scrubbing operation has already been demonstrated. Although the multi-context scrubbing operation presents the benefit that it can treat both soft errors and permanent failures caused by radiation simultaneously, the conventional contributions have never presented how to maintain the state of a sequential circuit after a permanent failure occurs on flip-flops. Therefore, in the conventional multi-context scrubbing operation, all the operations must be restarted from the initial condition each time a permanent failure occurs on a programmable gate array. As a result, conventional multi-context scrubbing operations could not be applied for real-time systems. The proposed optical multi-context scrubbing method that can solve the issue has been experimentally evaluated on a radiation-hardened optically reconfigurable gate array.
en-copyright=
kn-copyright=

en-aut-name=AndoKakeru
en-aut-sei=Ando
en-aut-mei=Kakeru
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=1
ORCID=

en-aut-name=WatanabeMinoru
en-aut-sei=Watanabe
en-aut-mei=Minoru
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=2
ORCID=

en-aut-name=WatanabeNobuya
en-aut-sei=Watanabe
en-aut-mei=Nobuya
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=3
ORCID=

affil-num=1
en-affil=Graduate School of Natural Science and Technology, Okayama University
kn-affil=

affil-num=2
en-affil=Faculty of Environmental, Life, Natural Science and Technology, Okayama University
kn-affil=

affil-num=3
en-affil=Faculty of Environmental, Life, Natural Science and Technology, Okayama University
kn-affil=
END

start-ver=1.4
cd-journal=joma
no-vol=31
cd-vols=
no-issue=2
article-no=
start-page=1943
end-page=1957
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2023
dt-pub=20230116
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=High-sensitivity low-noise photodetector using a large-area silicon photomultiplier
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=The application of silicon photomultiplier (SiPM) technology for weak-light detection at a single photon level has expanded thanks to its better photon detection efficiency in comparison to a conventional photomultiplier tube (PMT). SiPMs with large detection area have recently become commercially available, enabling applications where the photon flux is low both temporarily and spatially. On the other hand, several drawbacks exist in the usage of SiPMs such as a higher dark count rate, many readout channels, slow response time, and optical crosstalk; therefore, users need to carefully consider the trade-offs. This work presents a SiPM-embedded compact large-area photon detection module. Various techniques are adopted to overcome the disadvantages of SiPMs so that it can be generally utilized as an upgrade from a PMT. A simple cooling component and recently developed optical crosstalk suppression method are adopted to reduce the noise which is more serious for larger-area SiPMs. A dedicated readout circuit increases the response frequency and reduces the number of readout channels. We favorably compare this design with a conventional PMT and obtain both higher photon detection efficiency and larger-area acceptance.
en-copyright=
kn-copyright=

en-aut-name=MasudaTakahiko
en-aut-sei=Masuda
en-aut-mei=Takahiko
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=1
ORCID=

en-aut-name=HiramotoAyami
en-aut-sei=Hiramoto
en-aut-mei=Ayami
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=2
ORCID=

en-aut-name=AngDaniel G.
en-aut-sei=Ang
en-aut-mei=Daniel G.
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=3
ORCID=

en-aut-name=MeisenhelderCole
en-aut-sei=Meisenhelder
en-aut-mei=Cole
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=4
ORCID=

en-aut-name=PandaCristian D.
en-aut-sei=Panda
en-aut-mei=Cristian D.
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=5
ORCID=

en-aut-name=SasaoNoboru
en-aut-sei=Sasao
en-aut-mei=Noboru
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=6
ORCID=

en-aut-name=UetakeSatoshi
en-aut-sei=Uetake
en-aut-mei=Satoshi
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=7
ORCID=

en-aut-name=WuXing
en-aut-sei=Wu
en-aut-mei=Xing
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=8
ORCID=

en-aut-name=DeMilleDavid P.
en-aut-sei=DeMille
en-aut-mei=David P.
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=9
ORCID=

en-aut-name=DoyleJohn M.
en-aut-sei=Doyle
en-aut-mei=John M.
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=10
ORCID=

en-aut-name=GabrielseGerald
en-aut-sei=Gabrielse
en-aut-mei=Gerald
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=11
ORCID=

en-aut-name=YoshimuraKoji
en-aut-sei=Yoshimura
en-aut-mei=Koji
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=12
ORCID=

affil-num=1
en-affil=Research Institute for Interdisciplinary Science, Okayama University
kn-affil=

affil-num=2
en-affil=Research Institute for Interdisciplinary Science, Okayama University
kn-affil=

affil-num=3
en-affil=Department of Physics, Harvard University
kn-affil=

affil-num=4
en-affil=Department of Physics, Harvard University
kn-affil=

affil-num=5
en-affil=Department of Physics, University of California
kn-affil=

affil-num=6
en-affil=Research Institute for Interdisciplinary Science, Okayama University
kn-affil=

affil-num=7
en-affil=Research Institute for Interdisciplinary Science, Okayama University
kn-affil=

affil-num=8
en-affil=2Department of Physics, Harvard University
kn-affil=

affil-num=9
en-affil=James Franck Institute and Department of Physics, University of Chicago
kn-affil=

affil-num=10
en-affil=Research Institute for Interdisciplinary Science, Okayama University
kn-affil=

affil-num=11
en-affil=Center for Fundamental Physics, Department of Physics and Astronomy, Northwestern University
kn-affil=

affil-num=12
en-affil=Research Institute for Interdisciplinary Science, Okayama University
kn-affil=
END