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Journal Articles

Photoelectron diffraction from laser-aligned molecules with X-ray free-electron laser pulses

Nakajima, Kyo*; Teramoto, Takahiro*; Akagi, Hiroshi; Fujikawa, Takashi*; Majima, Takuya*; Minemoto, Shinichiro*; Ogawa, Kanade*; Sakai, Hirofumi*; Togashi, Tadashi*; Tono, Kensuke*; et al.

Scientific Reports (Internet), 5, p.14065_1 - 14065_11, 2015/09

 Times Cited Count:29 Percentile:83.61(Multidisciplinary Sciences)

We report on the measurement of deep inner-shell 2p X-ray photoelectron diffraction (XPD) patterns from laser-aligned I$$_{2}$$ molecules using X-ray free-electron laser (XFEL) pulses. The XPD patterns of the I$$_{2}$$ molecules, aligned parallel to the polarization vector of the XFEL, were well matched with our theoretical calculations. Further, we propose a criterion for applying our molecular-structure-determination methodology to the experimental XPD data. In turn, we have demonstrated that this approach is a significant step toward the time-resolved imaging of molecular structures.

Journal Articles

Stabilization of a high-order harmonic generation seeded extreme ultraviolet free electron laser by time-synchronization control with electro-optic sampling

Tomizawa, Hiromitsu*; Sato, Takahiro*; Ogawa, Kanade*; Togawa, Kazuaki*; Tanaka, Takatsugu*; Hara, Toru*; Yabashi, Makina*; Tanaka, Hitoshi*; Ishikawa, Tetsuya*; Togashi, Tadashi*; et al.

High Power Laser Science and Engineering, 3, p.e14_1 - e14_10, 2015/04

 Times Cited Count:4 Percentile:29.28(Optics)

no abstracts in English

Journal Articles

Full-coherent HHG-seeded EUV-FEL locked by EOS timing feedback

Ogawa, Kanade*; Sato, Takahiro*; Matsubara, Shinichi*; Okayasu, Yuichi*; Togashi, Tadashi*; Watanabe, Takahiro*; Takahashi, Eiji*; Midorikawa, Katsumi*; Aoyama, Makoto; Yamakawa, Koichi; et al.

Proceedings of 10th Conference on Lasers and Electro-Optics Pacific Rim and 18th OptoElectronics and Communications Conference and Photonics in Switching 2013 (CLEO-PR & OECC/PS 2013) (USB Flash Drive), 2 Pages, 2013/06

no abstracts in English

Journal Articles

High intense full-coherent radiation of free electron laser seeded by high-order harmonics in extreme-ultraviolet region

Togashi, Tadashi*; Takahashi, Eiji*; Midorikawa, Katsumi*; Aoyama, Makoto; Yamakawa, Koichi; Sato, Takahiro*; Iwasaki, Atsushi*; Owada, Shigeki*; Yamanouchi, Kaoru*; Hara, Toru*; et al.

Proceedings of Ultrafast Optics IX (CD-ROM), 2 Pages, 2013/03

We have demonstrated free-electron laser radiation seeded by high-order harmonics in the extreme-ultraviolet region. Strong enhancement of the radiation intensity by a factor of 104 was observed with timing control of an electro-optical sampling technique.

Journal Articles

The First electron bunch measurement by means of dast organic EO crystals

Okayasu, Yuichi*; Tomizawa, Hiromitsu*; Matsubara, Shinichi*; Sato, Takahiro*; Ogawa, Kanade*; Togashi, Tadashi*; Takahashi, Eiji*; Minamide, Hiroaki*; Matsukawa, Ken*; Aoyama, Makoto; et al.

Proceedings of 1st International Beam Instrumentation Conference (IBIC 2012) (Internet), 5 Pages, 2012/10

no abstracts in English

Journal Articles

Compensation of residual third-order dispersion in a fiber stretched, chirped-pulse amplification system using a grism pair

Ogawa, Kanade; Akahane, Yutaka; Tsuji, Koichi; Yamakawa, Koichi

Reza Kenkyu, 38(10), p.779 - 783, 2010/10

We have newly designed a grism pair compensator for third-order dispersion in a fiber stretched chirped-pulse amplification system. In a numerical calculation, we have obtained a pedestal-free re-compressed pulse close to the transform-limited pulse using the grism pair. We have experimentally demonstrated a two-fold enhancement of peak intensity and pulse shortening of the compressed pulse with this device.

Journal Articles

Compression of idler pulses with an identical positive dispersive media to signal pulse stretcher in ultrafast optical-parametric chirped-pulse amplification

Akahane, Yutaka; Ogawa, Kanade; Tsuji, Koichi; Aoyama, Makoto; Yamakawa, Koichi

Proceedings of SPIE, Vol.7589, p.75890L_1 - 75890L_8, 2010/02

 Times Cited Count:0 Percentile:0.01

We have proposed and demonstrated a very simple and robust femtosecond optical-parametric chirped-pulse amplification scheme in which an even order dispersion of an idler pulse is compensated by passing through an identical positive dispersive material used for temporal stretching a signal pulse. By compressing the idler pulses having a negatively chirp in this manner, high power sub-100 fs pulses were successfully obtained with only a transparent glass block used for the stretcher and compressor.

Journal Articles

Optical-parametric chirped-pulse amplification using a positive dispersive material for pulse stretching and compression

Yamakawa, Koichi; Akahane, Yutaka; Ogawa, Kanade; Aoyama, Makoto

Denki Gakkai Hikari, Ryoshi Debaisu Kenkyukai Shiryo OQD-09-61, p.13 - 16, 2009/09

We have proposed and demonstrated a novel optical-parametric chirped-pulse amplification scheme in which an even order dispersion of an idler pulse is compensated by passing through an identical positive dispersive material used for temporal stretching a signal pulse. By compressing the idler pulses having a negatively chirp in this manner, high power sub-100 fs pulses were successfully obtained with only a transparent glass block used for the stretcher and compressor. A feasible design of real world femtosecond laser systems employing this scheme is also discussed.

Journal Articles

Idler pulse compression using an identical positive stretcher/compressor combination in optical-parametric chirped-pulse amplification

Akahane, Yutaka; Ogawa, Kanade; Tsuji, Koichi; Aoyama, Makoto; Yamakawa, Koichi

Applied Physics Express, 2(7), p.072503_1 - 072503_3, 2009/07

 Times Cited Count:4 Percentile:19.88(Physics, Applied)

We have proposed and demonstrated a very simple and robust femtosecond optical-parametric chirped-pulse amplification scheme in which an even order dispersion of an idler pulse is compensated by passing through an identical positive dispersive material used for temporal stretching a signal pulse. By compressing the idler pulses having a negatively chirp in this manner, high power sub-100 fs pulses were successfully obtained with only a transparent glass block used for the stretcher and compressor. A feasible design of real world femtosecond laser systems employing this scheme is also discussed.

Journal Articles

Controlling the phase matching conditions of optical parametric chirped-pulse amplification using partially deuterated KDP

Ogawa, Kanade; Sueda, Keiichi*; Akahane, Yutaka; Aoyama, Makoto; Tsuji, Koichi; Fujioka, Kana*; Kanabe, Tadashi*; Yamakawa, Koichi; Miyanaga, Noriaki*

Optics Express (Internet), 17(10), p.7744 - 7749, 2009/05

 Times Cited Count:12 Percentile:54.45(Optics)

Using a partially deuterated KDP crystal for an optical parametric amplifier, we demonstrated ultrabroadband optical parametric chirped-pulse amplification of more than 250 nm bandwidth at a center wavelength of 1050 nm. We numerically show how to control the broadband phase matching conditions at different wavelengths to match center wavelengths of suitable broadband seed sources by adjusting the deuteration level in partially deuterated KDP.

Journal Articles

Ultrahigh intensity few-cycle lasers

Yamakawa, Koichi; Aoyama, Makoto; Akahane, Yutaka; Ogawa, Kanade; Tsuji, Koichi

Reza Kenkyu, 36(9), p.555 - 561, 2008/09

We review progress in the generation of ultrahigh-intensity optical pulses in a few-cycle regime. A design of a Generation of ENergetic Beam Ultimate (GENBU) laser based on optical parametric chirped-pulse amplification, which will be produced a peak power of up to 6-PW with a variable pulse durations ranging from 5-fs to 8-ps is described. Ultra-broadband optical parametric chirped-pulse amplification pumped by a picosecond laser pulse delivered from a diode-pumped, cryogenically-cooled Yb:YLF chirped-pulse amplification laser is also reported.

Journal Articles

Bandwidth enhancement of optical parametric chirped pulse amplification by temporally delayed two pump beams

Ogawa, Kanade; Aoyama, Makoto; Akahane, Yutaka; Tsuji, Koichi; Kawanaka, Junji*; Harimoto, Tetsuo*; Nishioka, Hajime*; Fujita, Masayuki*; Yamakawa, Koichi

Japanese Journal of Applied Physics, 47(6), p.4592 - 4594, 2008/06

 Times Cited Count:7 Percentile:31.85(Physics, Applied)

We have demonstrated ultra-broadband optical parametric chirped-pulse amplification of more than 350 nm bandwidth in a near infrared region. We have observed a substantial enhancement (nearly 2-fold) of the parametric amplification bandwidth by using time delayed two broadband pump pulses at degeneracy.

Journal Articles

High-energy diode-pumped picosecond regenerative amplification at 999 nm in wavelength with a cryogenically cooled Yb:LuLiF$$_{4}$$ crystal

Akahane, Yutaka; Aoyama, Makoto; Sugiyama, Akira; Kubo, Ryoichi; Ogawa, Kanade; Tsuji, Koichi; Yamakawa, Koichi

Optics Letters, 33(5), p.494 - 496, 2008/03

 Times Cited Count:2 Percentile:15.43(Optics)

A diode-pumped, cryogenically-cooled Yb:LuLiF$$_{4}$$ regenerative amplifier has been developed for the first time to our knowledge. A chirped-seed pulse was amplified and compressed in the regenerative amplifier, simultaneously, which generated $$sim$$6-mJ, 13-ps pulses at 999 nm wavelength without a pulse compressor. Simultaneous lasing at 999 nm and 1024 nm, respectively, was demonstrated, which could be used for different frequency generation in the THz region.

Journal Articles

Ultra-broadband optical parametric chirped-pulse amplification with a diverged pump beam

Ogawa, Kanade; Akahane, Yutaka; Harimoto, Tetsuo*; Aoyama, Makoto; Tsuji, Koichi; Kawanaka, Junji*; Nishioka, Hajime*; Fujita, Masayuki*; Yamakawa, Koichi

Reza Kenkyu, 35(9), p.596 - 598, 2007/09

no abstracts in English

Journal Articles

Multi-millijoule, diode-pumped, cryogenically-cooled Yb:KY(WO$$_{4}$$)$$_{2}$$ chirped-pulse regenerative amplifier

Ogawa, Kanade; Akahane, Yutaka; Aoyama, Makoto; Tsuji, Koichi; Tokita, Shigeki*; Kawanaka, Junji*; Nishioka, Hajime*; Yamakawa, Koichi

Optics Express (Internet), 15(14), p.8598 - 8602, 2007/07

 Times Cited Count:21 Percentile:70.17(Optics)

Ytterbium (Yb$$^{3+}$$) doped gain media are one of promising laser materials for the next generation of diode-pumped high-power lasers. Yb-doped media have several advantages. It has wide absorption bandwidth, the low quantum defect, and the simple electronic structure. Yb:KY(WO$$_{4}$$)$$_{2}$$ (Yb:KYW) and Yb:KG(WO$$_{4}$$)$$_{2}$$ (Yb:KGW) have a large absorption and wide emission cross section, broad emission spectral range, and high thermal conductivity, yielding a high repetition-rate, high-energy, sub-picosecond pulses. However, multi-millijoule-class Yb:KYW or Yb:KGW lasers have not yet been reported so far, excepting a massive, joule-class Ti:sapphire laser pumped Yb:KGW regenerative amplifier. So, We developed a compact diode-pumped, cryogenically-cooled chirped-pulse Yb:KYW regenerative amplifier. An amplified pulse with an energy of 5.5 mJ and a high optical conversion efficiency of $$sim$$14% is achieved. Regenerative pulse shaping is also used to counter gain narrowing during amplification.

Journal Articles

High-energy, diode-pumped, picosecond Yb:YAG chirped-pulse regenerative amplifier for pumping optical parametric chirped-pulse amplification

Akahane, Yutaka; Aoyama, Makoto; Ogawa, Kanade; Tsuji, Koichi; Tokita, Shigeki*; Kawanaka, Junji*; Nishioka, Hajime*; Yamakawa, Koichi

Optics Letters, 32(13), p.1899 - 1901, 2007/07

 Times Cited Count:38 Percentile:84.44(Optics)

A diode-pumped, cryogenic-cooled Yb:YAG regenerative amplifier utilizing gain-narrowing has been developed. A 1.2-ns chirped-seed pulse was amplified and compressed in the regenerative amplifier, simultaneously, which generated a 35-ps pulse with $$sim$$8-mJ of energy without a pulse compressor. Second-harmonics of the amplified pulse was used to pump picosecond two-color optical parametric amplification.

Journal Articles

Degenerate optical parametric chirped-pulse amplifier pumped by an Yb:YLF chirped-pulse amplification laser

Aoyama, Makoto; Akahane, Yutaka; Ogawa, Kanade; Tsuji, Koichi; Sugiyama, Akira; Harimoto, Tetsuo*; Kawanaka, Junji*; Nishioka, Hajime*; Fujita, Masayuki*; Yamakawa, Koichi

Reza Kenkyu, 35(6), p.398 - 399, 2007/06

We have demonstrated optical parametric chirped-pulse amplification by using a diode-pumped Yb:YLF CPA laser system as a pump source and achieved an ultra-broadband amplification of over 200-nm supporting a 12.6-fs duration (3.7 optical cycles) in spite of being operated around degeneracy. By using a two-stage OPCPA with a higher-energy pump pulse, it should be able to produce a terawatt-class, few-cycle laser pulse without complexly and enlarging the system size. Such a laser is useful for the generation of attosecond pulse generation in the xuv region as well as other high field applications.

Oral presentation

Development of high-intensity few-cycle optical parametric chirped-pulse amplifiers pumped by an Yb:YLF chirped-pulse amplification laser

Aoyama, Makoto; Akahane, Yutaka; Tsuji, Koichi; Ogawa, Kanade; Harimoto, Tetsuo*; Kawanaka, Junji*; Nishioka, Hajime*; Fujita, Masayuki*; Yamakawa, Koichi

no journal, , 

no abstracts in English

Oral presentation

High-intensity few-cycle optical parametric chirped-pulse amplification system

Aoyama, Makoto; Akahane, Yutaka; Ogawa, Kanade; Tsuji, Koichi; Harimoto, Tetsuo*; Kawanaka, Junji*; Nishioka, Hajime*; Fujita, Masayuki*; Yamakawa, Koichi

no journal, , 

no abstracts in English

Oral presentation

Ultrabroadband optical parametric chirped-pulse amplification system, 1; System overview

Aoyama, Makoto; Akahane, Yutaka; Ogawa, Kanade; Tsuji, Koichi; Harimoto, Tetsuo*; Kawanaka, Junji*; Nishioka, Hajime*; Fujita, Masayuki*; Yamakawa, Koichi

no journal, , 

no abstracts in English

72 (Records 1-20 displayed on this page)