Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Zaitsu Shin-ichi Last modified date:2021.10.22

Associate Professor / Molecular Information System / Department of Applied Chemistry / Faculty of Engineering

1. Taku Shakano, Shin-ichi Zaitsu, Totaro Imasaka, Deep- to near-ultraviolet Raman frequency conversion pumped by femtosecond pulses in a hollow-core waveguide, APPLIED OPTICS, 10.1364/AO.424896, 60, 23, 6962-6970, 2021.08, Broadband vibrational/rotational Raman generation ranging from deep ultraviolet (DUV) to blue wavelengths is demonstrated by using molecular hydrogen in a hollow-core waveguide as a Raman-active medium pumped by a femtosecond DUV laser. We find the high-order transient stimulated Raman scattering is drastically enhanced for input beams including a circularly polarized component; a circularly polarized input beam achieves the highest conversion efficiency. Coherent vibrational anti-Stokes Raman emission is observed only for a circularly polarized pump beam, indicating that the waveguide effect also contributes to the upconversion of a DUV pulse via transient stimulated Raman scattering. (C) 2021 Optical Society of America..
2. Zaitsu Shin-Ichi, Takumi Tanabe, Kota Oshima, Hiroyuki Hirata, Theoretical analysis of a molecular optical modulator for a continuous-wave laser based on a hollow-core photonic crystal fiber, Applied Sciences, 10.3390/app8101895, 8, 10, 2018.10, A THz optical modulator for a continuous-wave laser using a hollow-core photonic crystal fiber (HC-PCF) was proposed and theoretically analyzed. Lightwaves traveling through the HC-PCF is modulated by interactions with coherently driven Raman-active molecules in the core. The coherent molecular motion is excited by a pulse train having an interval between successive pulses shorter than the molecular dephasing time. In principle, a rotational transition of molecular hydrogen (S0(1)) at a pressure of 1 atm has a long enough dephasing time to maintain molecular coherence during a 1 GHz commercially available mode-locked pulse train. Optimization of the waveguide dispersion would enable phase-matching between the probe beam and generated sidebands during optical modulation. The proposed scheme would be achievable with a reasonable pump beam power and HC-PCF length, and with a feasible pressure of molecules in the core..
3. Zaitsu Shin-Ichi, Takao Tsuchiya, A Molecularly Modulated Mode-Locked Laser, Scientific Reports, 10.1038/s41598-018-30743-9, 8, 1, 2018.12, A mode-locked laser operating at a frequency over 10 THz is reported, which is three orders of magnitude greater than a standard mode-locked laser. The system used molecules with a Raman gain as an amplifier, while coherent molecular motions were used for optical modulation. Molecules in a high-finesse optical cavity modulated a continuous-wave beam to produce a train of ultrashort optical pulses at a repetition rate corresponding to the frequency of molecular motion. Phase-locking was achieved by an appropriate compensation of the total dispersion of the optical cavity. Thus, the oscillating multiple longitudinal modes were all coupled under phase-matching conditions of parametric four-wave mixing..
4. Shin-ichi Zaitsu, Hirotomo Izaki, Takao Tsuchiya, Totaro Imasaka, Continuous-wave phase-matched molecular optical modulator, SCIENTIFIC REPORTS, 6, 20908, 2016.01.
5. Shin-ichi Zaitsu, Totaro Imasaka, Continuous-wave anti-Stokes Raman laser based on phase-matched nondegenerate four-wave mixing, OPTICS LETTERS, 10.1364/OL.40.000073, 40, 1, 73-76, 2015.01.
6. Jumpei Takabayashi, Shin-ichi Zaitsu, Totaro Imasaka, Generation of three-primary-color Raman comb in the continuous-wave regime, APPLIED PHYSICS B-LASERS AND OPTICS, 10.1007/s00340-014-5856-4, 117, 1, 465-470, 2014.10.
7. Shin-ichi Zaitsu, Totaro Imasaka, Intracavity Phase-matched Coherent Anti-stokes Raman Spectroscopy for Trace Gas Detection, ANALYTICAL SCIENCES, 30, 1, 75-79, 2014.01.
8. Yuich Hashiguchi, Shin-ichi Zaitsu, Totaro IMASAKA, Ionization of pesticides using a far-ultraviolet femtosecond laser in gas chromatography/time-of-flight mass spectrometry, ANALYTICAL AND BIOANALYTICAL CHEMISTRY, 10.1007/s00216-013-6976-0, 405, 22, 7053-7059, 2013.04.
9. Shin-ichi Zaitsu, Totaro Imasaka, Phase-matched generation of high-order continuous-wave coherent Raman sidebands, Optics Communications, 285, 347-351, 2012.02.
10. Shin-ichi Zaitsu, Totaro Imasaka, Control of quantum pathways for the generation of continuous-wave Raman sidebands, 
Optics Express, 19, 24298-24307, 2011.11.
11. Shin-ichi Zaitsu, Totaro Imasaka, Continuous-wave multifrequency laser emission generated through stimulated Raman scattering and four-wave Raman mixing in an optical cavity, 
IEEE Journal of Quantum Electronic, 47, 1129-1135, 2011.08.
12. Yuki Miyoshi, Shin-ichi Zaitsu, Totaro Imasaka, In situ third-order interferometric autocorrelation of a femtosecond deep-ultraviolet pulse, Applied Physics B, 103, 789-795, 2011.04.
13. Fumiaki Yasaka, Yuichiro Kida, Shin-ichi Zaitsu, Totaro Imasaka,, Generation of high-order rotational Raman sidebands in the deep-ultraviolet region using molecular phase modulation induced by an intensity-modulated optical pulse, Journal of Applied Physics, 108, 056104, 2010.05.
14. Takashi Shimizu, Yuka Watanabe-Ezoe, Satoshi Yamaguchi, Hiroko Tsukatani, Tomoko Imasaka, Shin-ichi Zaitsu, Tomohiro Uchimura, Totaro Imasaka, Enhancemont of melecular ions in mass spectrometry using an ultrashort optical pulse in multiphoton ionization, Analytical Chemistry, Vol. 82, 3441–3444 (2010), 2010.04.
15. Shin-ichi Zaitsu, Totaro Imasaka, Quantitative measurement of the phase-locking of highly repetitive ultrashort optical pulses generated by a multifrequency contiuous Raman laser, Applied Optics, Vol. 49, 1586-1592 (2010), 2010.03.
16. Yuichiro Kida, Shin-ichi Zaitsu, Totaro Imasaka, Coherent molecular rotations induced by a femtosecond pulse consisting of two orthogonally polarized pulses, Physical Review A,, Vol. 80, 021805(R) (2009), 2009.04.
17. Satoshi Yamaguchi, Fumiaki Kira, Yuki Miyoshi, Tomohiro Uchimura, Yuka Watanabe-Ezoe, Shin-ichi Zaitsu, Tomoko Imasaka, Totaro Imasaka, Near-ultraviolet femtosecond laser ionization of dioxines in gas chromatography/time-of-flight mass spectrometry, Analytica Chimica Acta, Vol. 632, 229-233 (2009), 2008.11.
18. Yuichiro Kida, Shin-ichi Zaitsu, Totaro Imasaka, Generation of intense 11-fs ultraviolet pulses using phase modulation by two types of coherent molecular motions, Optics Express, Vol. 16, 13492-13498 (2008), 2008.09.
19. Yuichiro Kida, Shin-ichi Zaitsu, Totaro Imasaka, Stimulated rotational Raman scattring by a polarization-modulated femtosecond pulse, Physical Review A,, Vol. 77, 063802 (2008), 2008.06.
20. Shin-ichi Zaitsu, Hirotomo Izaki, Totaro Imasaka, Phase-matched Raman resonant four-wave mixing in a dispersion-compensated high-finesse optical cavity, Physical Review Letters, Vol. 100, 073901, 2008.01.
21. Shin-ichi Zaitsu, Yuki Miyoshi, Fumiaki Kira, Satoshi Yamaguchi, Tomohiro Uchimura, Tatoro Imasaka, Interferometric characterization of ultrashort deep ultraviolet pulses using a multiphoton ionization mass spectrometer, Optics Letters, Vol. 32, 1716-1718, 2007.08.
22. Teppei Sotoda, Shin-ichi Zaitsu, Totaro Imasaka, The efficient generation of a three-primary-color laser from the second harmonic emission of a Nd:YAG laser, Applied Optics, Vol. 46, 3001-3006, 2007.05.
23. Shin-ichi Zaitsu, Chihiro Eshima, Kazuki Ihara, Totaro Imasaka, Generation of a continuous-wave pulse train at a repetition rate of 17.6 THz, Journal of the Optical Society of America B, Vol. 24, 1037-1041, 2007.05.
24. Kazuki Ihara, Shin-ichi Zaitsu, Chihiro Eshima, Totaro Imasaka, Autocorrelator for the measurement of a quasi-continuous-wave laser beam sinusoidally modulated at 17 THz, Science and Technology of Advanced Materials, Vol. 7, 711-713 , 2006.12.
25. Fumiaki Kira, Masahiro Matsuse, Shin-ichi Zaitsu, Totaro Imasaka,, Efficient generation of vibrational stimulated Raman emission in the ultraviolet region using a femtosecond pump beam, Optics Communications, Vol. 265, 603~606, 2006.04.
26. Yuichiro Kida, Tetsuhiko Nagahara, Shin-ichi Zaitsu, Masahiro Matsuse, Totaro Imasaka, Pulse compression based on coherent molecular motion induced by transient stimulated Raman scattering, Optics Express, Vol. 14, 3038~3092, 2006.04.
27. Kazuki Ihara, Chihiro Eshima, Shin-ichi Zaitsu, Shingo Kamitomo, Kenji Shinzen, Yasuyuki Hirakawa, Totaro Imasaka, Ultrafast molecular-optic modulator, Applied Physics Letters, Vol. 88, 074101, 2006.01.
28. Shin-ichi Zaitsu, Yuichiro Kida, Totaro Imasaka, Stimulated Raman scattering in the boundary region between impulsive and nonimpulsive excitation, Journal of the Optical Society of America B, 10.1364/JOSAB.22.002642, 22, 12, 2642-2650, Vol. 22, 2642~2650, 2005.01.
29. Kazuki Ihara, Shin-ichi Zaitsu, Totaro Imasaka, Autocorrelator consisting of a solar-blind photomultiplier for use in the near-ultraviolet region, Review of Scientific Instruments, 10.1063/1.1850631, 76, 2, Vol. 76, 026109, 2005.01.
30. Shin-ichi Zaitsu, Yuichiro Kida, Totaro Imasaka, Self-compression of a femtosecond pulse due to Raman coherence of rotational motions, Physical Review A, 10.1103/PhysRevA.70.031801, 70, 3, Vol. 70, 031801, 2004.01.
31. Yuichiro Kida, Masahiro Matsuse, Shin-ichi Zaitsu, Totaro Imasaka, Generation of a sub-20-fs single optical pulse by four-wave Raman mixing using two Raman cells filled with molecular hydrogen, Optics Letters, 10.1364/OL.29.002809, 29, 23, 2809-2811, Vol. 29, 2809~2811, 2004.01.
32. Hiroyuki Ohtsuka, Shin-ichi Zaitsu, Tomohiro Uchimura, Totaro Imasaka, Generation of an ultrashort optical pulse by four-wave Raman mixing in deuterium cooled at 77 K, Applied Physics B, 10.1007/s00340-004-1468-8, 78, 6, 745-751, Vol. 78, 745~751, 2004.01.
33. Shin-ichi Zaitsu, Shinji Motokoshi, Takahisa Jitsuno, Masahiro Nakatsuka, Tatsuhiko Yamanaka, Laser damage properties of optical coatings with nanoscale layers grown by atomic layer deposition, Japanese Journal of Applied Physic, 10.1143/JJAP.43.1034, 43, 3, 1034-1035, Vol. 43, 1034~1035, 2004.01.
34. Shin-ichi Zaitsu, Shinji Motokoshi, Takahisa Jitsuno, Masahiro Nakatsuka, Tatsuhiko Yamanaka, Optical thin films consisting of nanoscale laminated layers, Applied Physics Letters, Vol. 81, 2442~2444, 2002.01.
35. Shin-ichi Zaitsu, Shinji Motokoshi, Takahisa Jitsuno, Masahiro Nakatsuka, Tatsuhiko Yamanaka, Large-area optical coatings with uniform thickness grown by surface chemical reactions for high-power laser applications, Japanese Journal of Applied Physics, Vol. 41, 160~165, 2002.01.