FEL2011 - List of Authors (Yamamoto, N.)

Paper

Title

Page

Saturation Effect on VUV Coherent Harmonic Generation at UVSOR-II

212

T. Tanikawa
PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France
M. Adachi, M. Katoh, J. Yamazaki, H. Zen
UVSOR, Okazaki, Japan
M. Hosaka, Y. Taira, N. Yamamoto
Nagoya University, Nagoya, Japan

Light source by using a laser seeding technique are under development at the UVSOR-II electron storage ring. In the past experiments, we have succeeded in generating coherent harmonics (CHs) in deep ultraviolet (UV) and vacuum UV (VUV) region, and also in generating CH with variable polarizations in deep UV [1]. In previous conferences, we reported an introduction of new-constructed spectrometer for VUV and results of spectra measurement, undulator gap dependencies, and injection laser power dependencies on VUV CHs [2]. This time we have successfully observed saturation on CHs intensities and have found some interesting phenomena, which are the necessary power of injection laser to achieve the saturation of CHG is different in different harmonic orders, and the CH intensity is oscillated in deep saturated regime. In this conference, we will discuss the results of some systematic measurements and those analytical and particle tracking simulations.
[1] M. Labat, et al., Phys. Rev. Lett. 101 (2008) 164803
[2] T. Tanikawa, et al., Prc. 1st Int. Particle Accelerator Conf., Kyoto, 2010.
[3] T. Tanikawa, et al., Appl. Phys. Express 3 (2010) 122702

TUPA13

Present Status and Future Prospects of Project on Utilizing Coherent Light Sources for User Experiments at UVSOR-II

215

H. Zen, K. Hayashi, S.I. Kimura, E. Nakamura, J. Yamazaki
UVSOR, Okazaki, Japan
M. Adachi, M. Katoh
Sokendai - Okazaki, Okazaki, Aichi, Japan
M. Hosaka, Y. Takashima, N. Yamamoto
Nagoya University, Nagoya, Japan
T. Takahashi
Kyoto University, Research Reactor Institute, Osaka, Japan

Funding: Quantum Beam Technology Program supported by JST/MEXT (Japan)
We have been intensively developing coherent light sources utilizing electron bunches in the storage ring, UVSOR-II, by adding some external components to the ring. After successful generation of coherent synchrotron radiation (CSR) in THz range* and coherent harmonic generation (CHG) in DUV range** by using an intense driving laser, a 5-year new research project named as Quantum Beam Technology Program has been started from FY2008. The project includes introduction of new driving laser system, dedicated undulators and beamlines, and aims at utilizing those coherent radiations for user experiments. The new driving laser system has been installed last year. The undulators and beamlines are now under construction. Installation of those components will be finished before the conference. In the conference, we will report on the present status of system development and future plan of application experiments.
*M. Shimada et al., Japanese Journal of Applied Physics, vol. 46, pp. 7939-7944 (2007).
**M. Labat et al., European Physical Journal D, vol. 44, pp. 187-200 (2007).

WEOC4

Intense Coherent THz Synchrotron Radiation Induced by a Storage Ring FEL Seeded with a Femtosecond Laser

M. Hosaka, Y. Taira, Y. Takashima, N. Yamamoto
Nagoya University, Nagoya, Japan
M. Adachi, M. Katoh, T. Tanikawa, H. Zen
UVSOR, Okazaki, Japan
S. Bielawski, C. Szwaj
PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France
C. Evain
SOLEIL, Gif-sur-Yvette, France

Very recently, we have succeeded in seeding a resonator FEL by injecting an external femtosecond laser at the UVSOR-II storage ring [1]. Intense coherent synchrotron radiation (CSR) in the THz region from a bending magnet was observed when the seeded FEL was operated in the pulsed Q-switch mode [2]. We have also found that the CSR intensity depends on the pulse duration of the seed laser. The CSR intensity is enhanced with short pulse ~200 fsec and suppressed with longer pulse ~200 psec. Simultaneous measurement of the terahertz radiation and the FEL pulse reveals that the radiation is emitted in the growing phase of the Q-switch FEL pulse. We think that the CSR comes from repetitive interactions between the laser pulse and the electron bunch as the short pulse laser growth in the optical cavity. In the presentation, we will also discuss the production mechanism of the CSR.
[1] C. Szwaj et al., FEL2011, TUPB05, in this conference.
[2] H. Zen et al., FEL2011, TUPA13, in this conference.

Slides WEOC4 [2.715 MB]

WEPA18

Chirped Pulse Generation by CHG-FEL

366

H. Zen, T. Tanikawa
UVSOR, Okazaki, Japan
M. Adachi, M. Katoh
Sokendai - Okazaki, Okazaki, Aichi, Japan
M. Hosaka, N. Yamamoto
Nagoya University, Nagoya, Japan

Funding: Ministry of Education, Science, Sports and Culture, Grant-in-Aid for Young Scientists (B), 23760067 (Japan)
Coherent Harmonic Generation Free Electron Laser (CHG-FEL)* is one of the promising ways to generate coherent, femtosecond and short-wavelength optical pulses from electron bunches circulating in an electron storage ring. However, the CHG pulse energy becomes smaller as the shorter pulse of laser is used for driving CHG-FEL because the number of electrons which contribute to the CHG production is limited by the pulse duration of driving laser. We proposed “chirped pulse generation and compression of CHG-FEL” to overcome such trade-off relationship, and got a small budget for proof-of-principle experiments in DUV region. In the experiment, chirped DUV pulses will be generated by CHG-FEL driving with chirped laser, and the DUV pulses will be compressed by a pulse compressor. The pulse duration of CHG-FEL before and after the compressor will be measured by a crosscorrelator. The principle, strategy, present status, and future prospects will be presented in the conference.
*R. Coisson and F De Martini, Physics of Quantum Electronics (Addison−Wesley, 1982) vol. 9. chap. 42.

Paper	Title	Page
TUPA11	Saturation Effect on VUV Coherent Harmonic Generation at UVSOR-II	212
	T. Tanikawa PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France M. Adachi, M. Katoh, J. Yamazaki, H. Zen UVSOR, Okazaki, Japan M. Hosaka, Y. Taira, N. Yamamoto Nagoya University, Nagoya, Japan
	Light source by using a laser seeding technique are under development at the UVSOR-II electron storage ring. In the past experiments, we have succeeded in generating coherent harmonics (CHs) in deep ultraviolet (UV) and vacuum UV (VUV) region, and also in generating CH with variable polarizations in deep UV [1]. In previous conferences, we reported an introduction of new-constructed spectrometer for VUV and results of spectra measurement, undulator gap dependencies, and injection laser power dependencies on VUV CHs [2]. This time we have successfully observed saturation on CHs intensities and have found some interesting phenomena, which are the necessary power of injection laser to achieve the saturation of CHG is different in different harmonic orders, and the CH intensity is oscillated in deep saturated regime. In this conference, we will discuss the results of some systematic measurements and those analytical and particle tracking simulations. [1] M. Labat, et al., Phys. Rev. Lett. 101 (2008) 164803 [2] T. Tanikawa, et al., Prc. 1st Int. Particle Accelerator Conf., Kyoto, 2010. [3] T. Tanikawa, et al., Appl. Phys. Express 3 (2010) 122702

TUPA13	Present Status and Future Prospects of Project on Utilizing Coherent Light Sources for User Experiments at UVSOR-II	215
	H. Zen, K. Hayashi, S.I. Kimura, E. Nakamura, J. Yamazaki UVSOR, Okazaki, Japan M. Adachi, M. Katoh Sokendai - Okazaki, Okazaki, Aichi, Japan M. Hosaka, Y. Takashima, N. Yamamoto Nagoya University, Nagoya, Japan T. Takahashi Kyoto University, Research Reactor Institute, Osaka, Japan
	Funding: Quantum Beam Technology Program supported by JST/MEXT (Japan) We have been intensively developing coherent light sources utilizing electron bunches in the storage ring, UVSOR-II, by adding some external components to the ring. After successful generation of coherent synchrotron radiation (CSR) in THz range* and coherent harmonic generation (CHG) in DUV range** by using an intense driving laser, a 5-year new research project named as Quantum Beam Technology Program has been started from FY2008. The project includes introduction of new driving laser system, dedicated undulators and beamlines, and aims at utilizing those coherent radiations for user experiments. The new driving laser system has been installed last year. The undulators and beamlines are now under construction. Installation of those components will be finished before the conference. In the conference, we will report on the present status of system development and future plan of application experiments. M. Shimada et al., Japanese Journal of Applied Physics, vol. 46, pp. 7939-7944 (2007). *M. Labat et al., European Physical Journal D, vol. 44, pp. 187-200 (2007).

WEOC4	Intense Coherent THz Synchrotron Radiation Induced by a Storage Ring FEL Seeded with a Femtosecond Laser
	M. Hosaka, Y. Taira, Y. Takashima, N. Yamamoto Nagoya University, Nagoya, Japan M. Adachi, M. Katoh, T. Tanikawa, H. Zen UVSOR, Okazaki, Japan S. Bielawski, C. Szwaj PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France C. Evain SOLEIL, Gif-sur-Yvette, France
	Very recently, we have succeeded in seeding a resonator FEL by injecting an external femtosecond laser at the UVSOR-II storage ring [1]. Intense coherent synchrotron radiation (CSR) in the THz region from a bending magnet was observed when the seeded FEL was operated in the pulsed Q-switch mode [2]. We have also found that the CSR intensity depends on the pulse duration of the seed laser. The CSR intensity is enhanced with short pulse ~200 fsec and suppressed with longer pulse ~200 psec. Simultaneous measurement of the terahertz radiation and the FEL pulse reveals that the radiation is emitted in the growing phase of the Q-switch FEL pulse. We think that the CSR comes from repetitive interactions between the laser pulse and the electron bunch as the short pulse laser growth in the optical cavity. In the presentation, we will also discuss the production mechanism of the CSR. [1] C. Szwaj et al., FEL2011, TUPB05, in this conference. [2] H. Zen et al., FEL2011, TUPA13, in this conference.
	Slides WEOC4 [2.715 MB]

WEPA18	Chirped Pulse Generation by CHG-FEL	366
	H. Zen, T. Tanikawa UVSOR, Okazaki, Japan M. Adachi, M. Katoh Sokendai - Okazaki, Okazaki, Aichi, Japan M. Hosaka, N. Yamamoto Nagoya University, Nagoya, Japan
	Funding: Ministry of Education, Science, Sports and Culture, Grant-in-Aid for Young Scientists (B), 23760067 (Japan) Coherent Harmonic Generation Free Electron Laser (CHG-FEL)* is one of the promising ways to generate coherent, femtosecond and short-wavelength optical pulses from electron bunches circulating in an electron storage ring. However, the CHG pulse energy becomes smaller as the shorter pulse of laser is used for driving CHG-FEL because the number of electrons which contribute to the CHG production is limited by the pulse duration of driving laser. We proposed “chirped pulse generation and compression of CHG-FEL” to overcome such trade-off relationship, and got a small budget for proof-of-principle experiments in DUV region. In the experiment, chirped DUV pulses will be generated by CHG-FEL driving with chirped laser, and the DUV pulses will be compressed by a pulse compressor. The pulse duration of CHG-FEL before and after the compressor will be measured by a crosscorrelator. The principle, strategy, present status, and future prospects will be presented in the conference. *R. Coisson and F De Martini, Physics of Quantum Electronics (Addison−Wesley, 1982) vol. 9. chap. 42.