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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：8 Percentile：32.79(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.
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
)
chirped-pulse regenerative amplifierOgawa, 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：22 Percentile：68.83(Optics)Ytterbium (Yb
) 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) (Yb:KYW) and Yb:KG(WO) (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 
14% is achieved. Regenerative pulse shaping is also used to counter gain narrowing during 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：42 Percentile：84.31(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 8-mJ of energy without a pulse compressor. Second-harmonics of the amplified pulse was used to pump picosecond two-color optical parametric amplification.
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.
Nishioka, Hajime*; Kawanaka, Junji
Hikari Araiansu, 14(11), p.21 - 25, 2003/11
no abstracts in English
Kawanaka, Junji; Yamakawa, Koichi; Nishioka, Hajime*; Ueda, Kenichi*
Optics Letters, 28(21), p.2121 - 2123, 2003/11
Times Cited Count：86 Percentile：93.50(Optics)no abstracts in English
crystal at low temperatureKawanaka, Junji; Yamakawa, Koichi; Nishioka, Hajime*; Ueda, Kenichi*
Optics Express (Internet), 10(10), p.455 - 460, 2002/05
Times Cited Count：48 Percentile：84.57(Optics)no abstracts in English
Kawanaka, Junji; Yamakawa, Koichi; Nishioka, Hajime*; Ueda, Kenichi*
Proceedings of Conference on Lasers and Electro-Optics / Quantum Electronics and Laser Science Conference (CLEO/QELS 2002), p.CPDC8_1 - CPDC8_3, 2002/00
no abstracts in English
Kawanaka, Junji; Nishioka, Hajime*; Inoue, Norihiro*; Ueda, Kenichi*
Applied Optics, 40(21), p.3542 - 3546, 2001/07
Times Cited Count：57 Percentile：89.32(Optics)no abstracts in English
Kawanaka, Junji; Nishioka, Hajime*; Inoue, Norihiro*; Kubota, Yoshinori*; Ueda, Kenichi*
XIII International Symposium on Gas Flow and Chemical Lasers and High-Power Laser Conference (Proceedings of SPIE Vol.4184) (CD-ROM), 4 Pages, 2000/09
no abstracts in English
Akahane, Yutaka; Aoyama, Makoto; Ogawa, Kanade; Tsuji, Koichi; Sugiyama, Akira; Harimoto, Tetsuo*; Kawanaka, Junji*; Nishioka, Hajime*; Fujita, Masayuki*; Yamakawa, Koichi
no journal, ,
We present an ultra-broadband intense optical-parametric chirped-pulse amplification system pumped by a cryogenically-cooled Yb:YLF chirped-pulse amplification laser.
Ogawa, Kanade; Aoyama, Makoto; Akahane, Yutaka; Tsuji, Koichi; Harimoto, Tetsuo*; Kawanaka, Junji*; Nishioka, Hajime*; Fujita, Masayuki*; Yamakawa, Koichi
no journal, ,
We demonstrated ultra-broadband optical parametric chirped-pulse amplification using a picosecond broadband pump beam at a 1
m wavelength region. Using two broadband pump beams, an amplification bandwidth of more than 350 nm was achieved in a type-I BBO crystal with a gain of 3.2
10
.
Ogawa, Kanade; Aoyama, Makoto; Akahane, Yutaka; Tsuji, Koichi; Sueda, Keiichi*; Kawanaka, Junji*; Nishioka, Hajime*; Fujita, Masayuki*; Yamakawa, Koichi
no journal, ,
We have demonstrated ultra-broadband optical parametric chirped-pulse amplification of more than 500-nm bandwidth pumped by a diode-pumped, cryogenic-cooled Yb:YLF chirped-pulse amplification laser.
Akahane, Yutaka; Tomita, Hitoshi*; Ogawa, Kanade; Nishioka, Hajime*; Yamakawa, Koichi
no journal, ,
For generation of intense few-cycle laser pulse with our idler pulse compression scheme, we have now been studying residual high-order dispersion compensation of idler pulses with pump phase modulation. The pump pulse has a narrow bandwidth with respect to signal or idler pulses, which you can easily control the pump phase by spatial light modulator or other conventional devices. And once a proper phase modulation is fixed, you can apply the modulation by some robust device such as such fiber Bragg grating or volume Bragg grating in practical use. From the first phase measurement of OPA interacting pulses, we have found that the sign of the 3rd order dispersion of the idler pulse have been inverted from the signal one and the sign of 4th order have not been inverted, which had not been expected from theory without considering the effect from pump phase modulation.
Akahane, Yutaka; Aoyama, Makoto; Tsuji, Koichi; Kawanaka, Junji*; Nishioka, Hajime*; Yamakawa, Koichi
no journal, ,
no abstracts in English
Aoyama, Makoto; Akahane, Yutaka; Tsuji, Koichi; Ogawa, Kanade; Harimoto, Tetsuo*; Kawanaka, Junji*; Nishioka, Hajime*; Fujita, Masayuki*; Yamakawa, Koichi
no journal, ,
no abstracts in English
Akahane, Yutaka; Aoyama, Makoto; Ogawa, Kanade; Tsuji, Koichi; Tokita, Shigeki*; Kawanaka, Junji*; Nishioka, Hajime*; Yamakawa, Koichi
no journal, ,
A diode-pumped Yb:YAG regenerative amplifier utilizing gain-narrowing has been developed. A chirped-seed pulse was amplified and compressed in the regenerative amplifier, simultaneously, which generated the picosecond pulses with 8 mJ of energy without a pulse compressor.
) chirped-pulse regenerative amplifierAoyama, Makoto; Ogawa, Kanade; Akahane, Yutaka; Tsuji, Koichi; Tokita, Shigeki*; Kawanaka, Junji*; Nishioka, Hajime*; Yamakawa, Koichi
no journal, ,
no abstracts in English
Akahane, Yutaka; Aoyama, Makoto; Ogawa, Kanade; Tsuji, Koichi; Tokita, Shigeki*; Kawanaka, Junji*; Nishioka, Hajime*; Yamakawa, Koichi
no journal, ,
We have developed a narrowband Yb:YAG chirped-pulse regenerative amplifier using gain-narrowing, which is suitable for direct OPCPA pumping without pulse compression. A chirped-seed pulse was amplified and compressed in the regen, simultaneously, which generated the picosecond pulses with 7.5-mJ of energy without a pulse compressor. In the experiment, output pulse from a mode-locked oscillator was split into two beams, which were used as seed pulses for both Yb:YAG regen and OPCPA. The seed pulse for the regen was positively chirped to 1.2 ns by a PANDA fiber before amplification. An Yb:YAG was cooled by a liquid-nitrogen cryostat and fiber-coupled laser diode was used to pump the regen. A gain narrowed amplified bandwidth (from 17 nm to 0.5 nm) corresponded to 35 ps (FWHM) duration. We also performed a parametric amplification by using the frequency-doubled, 25-ps pump pulse. We have observed OPA spectra at 850 and 1200 nm, simultaneously, with the maximum OPA gain of 10
.
