Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Hiroaki Yoshioka Last modified date:2019.04.18

Assistant Professor / Department of I&E Visionaries / Faculty of Information Science and Electrical Engineering


Papers
1. Yuya Mikami, Hiroaki Yoshioka, Soichiro Ryu, Naoya Nishimura, Yuji Oki, Organic-inorganic hybrid microdisk laser with dye and silica mixed doping prepared by ink-jet printing method, Optics Express, 10.1364/OE.26.007140, 26, 6, 7140-7147, 2018.03, We developed an ink-jet printing method for fabricating inorganic microdisks at room temperature, which is much lower than the melting point of solid-state inorganic oxide, and have fabricated an organic-inorganic hybrid microdisk laser. Silica was used as the inorganic disk material, and microdisk-shaped aggregates were formed by the ink-jet printing method using a solution in which nanosilica particles were dispersed in propylene glycol monomethylether (PGME) solvent. Then, a microdisk capable of laser oscillation was also prepared by preliminarily adding the laser dye rhodamine 6G to the ink to form a mixed organic material. The structural evaluation of the printed microdisk was first conducted using an optical microscope, a scanning electron microscope (SEM), and an atomic force microscope (AFM). The results of laser oscillation evaluation by optical excitation showed that the printed microdisk sufficiently functions as an optical resonator with a low optical loss. In these evaluations, excellent values such as a surface roughness of 5.83 nm from root mean square (R. M. S.) which is one forth smaller than the particle diameter, and a laser oscillation threshold of 4.76 μJ/mm2 at a wavelength of 601.4 nm were obtained. To the best of our knowledge, this is the first time that an inorganic microdisk has been fabricated at room temperature to realize an organic-inorganic hybrid microdisk laser..
2. Cong Chen, Lei Wan, Hengky Chandrahalim, Jian Zhou, Hui Zhang, Sangha Cho, Ting Mei, Hiroaki Yoshioka, Huiping Tian, Naoya Nishimura, Xudong Fan, L. Jay Guo, Yuji Oki, Effects of edge inclination angles on whispering-gallery modes in printable wedge microdisk lasers, Optics Express, 10.1364/OE.26.000233, 26, 1, 233-241, 2018.01, The ink-jet technique was developed to print the wedge polymer microdisk lasers. The characterization of these lasers was implemented using a free-space optics measurement setup. It was found that disks of larger edge inclination angles have a larger free spectral range (FSR) and a lower resonance wavelength difference between the fundamental transverse electric (TE) and transverse magnetic (TM) whispering-gallery modes (WGMs). This behavior was also confirmed with simulations based on the modified Oxborrow’s model with perfectly matched layers (PMLs), which was adopted to accurately calculate the eigenfrequencies, electric field distributions, and quality parameters of modes in the axisymmetric microdisk resonators. Combined with the nearly equivalent quality factor (Q-factor) and finesse factor (F-factor) variations, the correlations between the TE and left adjacent TM modes were theoretically demonstrated. When the edge inclination angle is varied, the distinguishable mode distribution facilitates the precise estimation of a resonance wavelength shift. Therefore, the flexible and efficient nature of wedge polymer microdisk lasers extends their potential applications in precision sensing technology..
3. Keisuke Nakakubo, Hiroaki Nomada, Hiroaki Yoshioka, Kinichi Morita, Yuji Oki, Gallium and polydimethylsiloxane molding for self-organized spherical lens surface fabrication, Applied Optics, 10.1364/AO.56.009900, 56, 36, 9900-9906, 2017.12, We present a new fabrication method for optical surfaces using liquid metal molding. Common optical surfaces are fabricated by the polishing of glasses or plastics. By contrast, the fabrication method we propose involves the transfer of a spherical surface of liquid molded metal with silicone rubber. The concept presented in this paper is of a new molding method in which a mold is placed inside. The curvature can be controlled from ∼0.37 mm−1 to −0.37 mm−1 by wetting the liquid metal. An application of this method is to produce on-demand optical elements (e.g., lenses and mirrors)..
4. Hiroaki Nomada, Kinichi Morita, Hirokazu Higuchi, Hiroaki Yoshioka, Yuji Oki, Carbon–polydimethylsiloxane-based integratable optical technology for spectroscopic analysis, Talanta, 116, 428-432, 2017.05.
5. Hiroaki Yoshioka, Yuya Mikami, Soichiro Ryu, Shintaro Mitsui, Cong Chen, Naoya Nishimura, Yuji Oki, Silica-based Inorganic Microdisk Cavity by the Ink-jet Printing Method, CLEO: 2017, 2017.05.
6. Hiroaki Yoshioka, Controlling mobility speed of dye molecules in polydimethylsiloxane through molecular weight and solubility, OPTICAL MATERIALS EXPRESS, 10.1364/OME.6.003417, 6, 11, 3417-3426, 2016.11.
7. Harunobu Takeda, Cong Chen, Takeshi Komino, Hiroaki Yoshioka, Yuji Oki, Chihaya Adachi, 0.6-1.6 THz band spectroscopy of organic thermally activated delayed fluorescence materials, OPTICAL MATERIALS EXPRESS, 10.1364/OME.6.003045, 6, 10, 3045-3052, 2016.10.
8. Hiroaki Yoshioka, Cong Chen, Soichiro Ryu, Jifeng Li, Masaaki Ozawa, Yuji Oki, Ultra-low Threshold Lasing at 0.8 μm from Organic Microdisk Cavity by the Ink-jet Printing Method, CLEO: 2016, 2016.06.
9. Cong Chen, Jifeng Li, Soichiro Ryu, Hiroaki Yoshioka, Masaaki Ozawa, Yuji Oki, Spectroscopic behavior in whispering-gallery modes by edge formation of printed microdisk lasers, Proc. SPIE, 10.1117/12.2202423, 9668, 96685J, 2015.12.
10. Soichiro Ryu, Hiroaki Yoshioka, Cong Chen, Kei Yasui, Yuji Oki, High-Q Printable Polymer Microdisk without Etching, 2015 European Conference on Lasers and Electro-Optics - European Quantum Electronics Conference, 2015.06.
11. Mitsuhiro Nakano, Noboru Hirakawa, Hiroaki Yoshioka, Yuji Oki, On-site three-dimensional fabrication of organic optical system with micro-dispensing method, 3nd EOS Conference on Optofluidics (EOSOF 2015), 2015.06.
12. Hiroaki Yoshioka, Noboru Hirakawa, Mitsuhiro Nakano, Yuji Oki, On-Demand Fabrication of Micro-Wired Rods and Nano-Coupling Control for 3D Polymeric Optical System, CLEO: 2015, 2015.05.
13. Hiroaki Yoshioka, Tomoya Ota, Cong Chen, Soichiro Ryu, Kei Yasui, Yuji Oki, Extreme ultra-low lasing threshold of full-polymeric fundamental microdisk printed with room-temperature atmospheric ink-jet technique, SCIENTIFIC REPORTS, 10.1038/srep10623, 5, 2015.05, 円盤型レーザー素子は、髪の毛の太さ程度の円盤形状をした光を閉じ込め共振させる微小共振器(マイクロディスクキャビティー)から構成され、情報処理分野における集積光回路に実装可能な周波数コム発生素子、医療バイオ分野におけるウイルス1個程度を検出できる超高感度バイオセンサーなど多岐にわたる分野で応用が可能なことから近年大きな注目を集めている。しかしこの円盤型レーザー素子の作製には、従来、フォトリソグラフィー法といった半導体プロセスの高度な技術が用いられてきたため、工場・実験室レベルで扱うものという考えが当該研究分野では常識であった。そこで本研究ではインクジェット技術を利用した室温・大気圧下で作製できる全く新しい分散型産業を指向した「インクジェットレーザー印刷法」を確立した。これは、超省エネルギーの円盤型レーザー素子を必要な場所に必要な数だけ市販のインクジェットプリンターのように簡単に卓上印刷できるという極めて独創的な技術である。当該学術分野のデバイス作製難易度を大きく低下させる「作製プロセスの簡素化」に大きく貢献したことは言うまでもなく、特に簡素な手法でありながら作製されたレーザー素子は駆動に必要なエネルギー(レーザー発振しきい値)において世界記録(従来より22%低いエネルギー)の「超省エネルギー化」を達成したことは学術的貢献が極めて高い。.
14. Cong Chen, Soichiro Ryu, Hiroaki Yoshioka, Kei Yasui, Yuji Oki, Low-threshold lasing from organic and polymeric microdisk printed by room temperature atmosphere ink-jet technique, Proc. SPIE, 10.1117/12.2078965, 9360, 936007, 2015.03.
15. Tokuma Nakamichi, Yu Yang, Tomoya Ohta, Hiroaki Yoshioka, Masayuki Yahiro, Masanao Era, Hirofumi Watanabe, Yuanjing Cui, Yuji Oki, Guodong Qian, Stackable spectral-sensitive conductive films based on cyanine aggregates via an inkjet method, DYES AND PIGMENTS, 10.1016/j.dyepig.2013.03.013, 98, 3, 333-338, 2013.09.
16. Noboru Hirakawa, Hiroyuki Kubota, Hiroaki Yoshioka, Noriyasu Tarumi, Yoshio Kagebayashi, Yuji Oki, Micro-dispensing for three-dimensional direct fabrication of laser waveguides, 2013 18th OptoElectronics and Communications Conference held jointly with 2013 International Conference on Photonics in Switching, 2013.07.
17. Hiroaki Yoshioka, Yusuke Itoh, Ayumu Kiyomori, Yuji Oki, Degradation self-recovery and durability extension on solid-state dye laser in blue region, CLEO: 2013, OSA Technical Diges, 10.1364/CLEO_SI.2013.CF1I.5, 2013.05.
18. Tomoya Ota, Hiroaki Yoshioka, Kei Yasui, Daisuke Maeda, Yuji Oki, Printed Fabrication of Microdisk at Room Temperature, Proc. of 2nd EOS Conference on Optofluidics 2013, 2, 1569714735_1-1569714735_2, 2013.05.
19. Kota Kuwamitsu, Hiroaki Yoshioka, Nahoko Naruishi, Yoshihide Tanaka, Yuji Oki, Print-like Fabrication of Laser Systems in PDMS Flowchip, Proc. of 2nd EOS Conference on Optofluidics 2013, 2, 1569714773_004_1-1569714773_004_2, 2013.05.
20. Hiroaki Yoshioka, Yuji Oki, Nd:YAG/Cr:GSGG passively Q-switched compact DPSS laser with flexure-frame structure, The 1st. Laser Ignition Conference '13, LIC4-3-1-LIC4-3-2, 2013.04.
21. Hiroaki Yoshioka, Yusuke Itoh, Ayumu Kiyomori, Masanao Era, Yuji Oki, Fluorene-based chromophore for degradation-recoverable solid-state dye laser, OPTICAL MATERIALS EXPRESS, 3, 2, 176-183, 2013.01.
22. Yu Yang, Tokuma Nakamichi, Hiroaki Yoshioka, Masayuki Yahiro, Masanao Era, Hirofumi Watanabe, Yuanjing Cui, Yuji Oki, Guodong Qian, Spectral-resolving capable and integratable multilayered conductive films via an inkjet method, JOURNAL OF MATERIALS CHEMISTRY C, 10.1039/c2tc00743f, 1, 9, 1739-1744, 2013.01.
23. Hiroyuki Kubota, Soichiro Oomi, Hiroaki Yoshioka, Hirofumi Watanabe, Yuji Oki, Optical bending sensor using distributed feedback solid state dye lasers on optical fiber, OPTICS EXPRESS, 20, 14, 14938-14944, 2012.07.
24. Hiroaki Yoshioka, Wataru Iwasaki, Yukihiro Yamashita, Nobuo Miyadera, Kei Yasui, Daisuke Maeda, Yuji Oki, Nd3+-TFA:HPDA Polymeric Microchip Laser, 2012 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO), 2012.05.
25. Hiroaki Yoshioka, Yu Yang, Hirofumi Watanabe, Yuji Oki, Fundamental characteristics of degradation-recoverable solid-state DFB polymer laser, OPTICS EXPRESS, 20, 4, 4690-4696, 2012.02.
26. Kota Kuwamitsu, Hiroaki Yoshioka, Ryo Goto, Hirofumi Watanabe, Nahoko Naruishi, Yoshihide Tanaka, Yuji Oki, Integration of Distributed-feedback (DFB) Solid-state Dye Lasers with Optical Pumping Systems for PDMS Micro Biochemistry Chips, IQEC/CLEO Pacific Rim 2011, 378-380, 2011.08.
27. Hiroaki Yoshioka, Wang Weibo, Kota Kuwamitsu, Wataru Iwasaki, Yukihiko Yamashita, Noboru Miyadera, Yuji Oki, Laser Action of Nd-Complex-Doped Polymer Laser Based on Liquid, MOLECULAR CRYSTALS AND LIQUID CRYSTALS, 10.1080/15421406.2011.566444, 539, 225-230, 2011.05.
28. Yu Yang, Tokuma Nakamichi, Hiroaki Yoshioka, Soichiro Omi, Ryo Goto, Hirofumi Watanabe, Yuji Oki, Intensity Sensitive Organic Photodiodes Patterned by Inkjet Method, MOLECULAR CRYSTALS AND LIQUID CRYSTALS, 10.1080/15421406.2011.563689, 538, 136-142, 2011.05.
29. Hiroaki Yoshioka, Ryo Goto, Soichiro Omi, Yu Yang, Yuji Oki, Degradation Recoverable DFB Lasers Based on P597:PDMS/PTFEMA, The European Conference on Lasers and Electro-Optics (CLEO/Europe) 2011 paper:, 2011.05.
30. Tokuma Nakamichi, Yu Yang, Soichiro Omi, Hiroaki Yoshioka, Hirofumi Watanabe, Masayuki Yahiro, Masanao Era, Yuji Oki, Monochromatic Organic Photodiodes Made by Stackable Ink-jet Fabrication for Integrated Laser Chips, 2011 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO), 2011.05.
31. Hiroaki Yoshioka, Ryo Goto, Soichiro Omi, Yu Yang, Yuji Oki, Solid-State Polymer Waveguide DFB Laser with Self Dye-Circulatory Function, 2011 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO), 2011.05.
32. Soichiro Omi, Hiroyuki Kubota, Hiroaki Yoshioka, Hirofumi Watanabe, Yuji Oki, Direct Laser fabrication on Polymeric Optical Fiber and Its Sensor Application, CLEO: Science and Innovations (CLEO: S and I) 2011 paper:, 2011.05.
33. Tokuma Nakamichi, Yu Yang, Hiroaki Yoshioka, Soichiro Omi, Hirofumi Watanabe, Yuji Oki, Printable DFB Laser and Wavelength Monitor Systems by On Demand Fabrication on Flexible Films, 2011 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO), 2011.05.
34. Hiroaki Yoshioka, Wang Weibo, Kota Kuwamitsu, Wataru Iwasaki, Yukihiko Yamashita, Nobuo Miyadera, Yuji Oki, High Efficient Laser Action by Nd3+ Complex, 2011 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO), 2011.05.
35. Hiroaki Yoshioka, Shinki Nakamura, Takayo Ogawa, Satoshi Wada, Dual-wavelength mode-locked Yb:YAG ceramic laser in single cavity, 2010 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) AND QUANTUM ELECTRONICS AND LASER SCIENCE CONFERENCE (QELS), 2010.05.
36. Hiroaki Yoshioka, Shinki Nakamura, Takayo Ogawa, Satoshi Wada, Dual-wavelength mode-locked Yb:YAG ceramic laser in single cavity, OPTICS EXPRESS, 18, 2, 1479-1486, 2010.01.
37. Hiroaki Yoshioka, Shinki Nakamura, Takayo Ogawa, Satoshi Wada, 233-fs mode-locked Yb:YAG ceramic laser, 2009 LASERS & ELECTRO-OPTICS & THE PACIFIC RIM CONFERENCE ON LASERS AND ELECTRO-OPTICS, VOLS 1 AND 2, 1248-1249, 2009.09.
38. Shinki Nakamura, Hiroaki Yoshioka, Takayo Ogawa, Satoshi Wada, Broadly Tunable Yb3+-Doped Y3Al5O12 Ceramic Laser at Room Temperature, JAPANESE JOURNAL OF APPLIED PHYSICS, 10.1143/JJAP.48.060205, 48, 6, 2009.06.
39. Hiroaki Yoshioka, Shinki Nakamura, Takayo Ogawa, Satoshi Wada, Diode-Pumped Mode-Locked Yb:YAG Ceramic Laser, 2009 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) AND INTERNATIONAL QUANTUM ELECTRONICS CONFERENCE (IQEC), 2009.06.
40. Hiroaki Yoshioka, Shinki Nakamura, Takayo Ogawa, Satoshi Wada, Diode-pumped mode-locked Yb:YAG ceramic laser, OPTICS EXPRESS, 17, 11, 8919-8925, 2009.05.
41. Shinki Nakamura, Hiroaki Yoshioka, Yu Matsubara, Takayo Ogawa, Satoshi Wada, Efficient tunable Yb : YAG ceramic laser, OPTICS COMMUNICATIONS, 10.1016/j.optcom.2008.05.009, 281, 17, 4411-4414, 2008.09.
42. Hiroaki Yoshioka, Shinki Nakamura, Yu Matsubara, Takayo Ogawa, Satoshi Wada, Efficient tunable diode-pumped Yb:YAG ceramic laser, 2008 CONFERENCE ON LASERS AND ELECTRO-OPTICS & QUANTUM ELECTRONICS AND LASER SCIENCE CONFERENCE, VOLS 1-9, 2601-2602, 2008.05.
43. Shinki Nakamura, Hiroaki Yoshioka, Yu Matsubara, Takayo Ogawa, Satoshi Wada, 6.8-W High Efficiency Yb:YAG Ceramic Laser at Room Temperature, The Review of Laser Engineering, 36, 1073-1076, 2008.01.