High-efficiency contact grating fabricated on the basis of a Fabry-Perot type resonator for terahertz wave generation

Yoshida, Fumiko; Nagashima, Keisuke; Tsubouchi, Masaaki; Ochi, Yoshihiro; Maruyama, Momoko; Sugiyama, Akira

Japanese Journal of Applied Physics, 55(1), p.012201_1 - 012201_5, 2016/01

https://doi.org/10.7567/JJAP.55.012201

Development of multi pass pumping module for thin disk laser material

Okada, Hajime; Maruyama, Momoko; Ochi, Yoshihiro; Nagashima, Keisuke

JAEA-Technology 2015-029, 29 Pages, 2015/11

JAEA-Technology-2015-029.pdf:11.21MB

We develop high repetitive and short pulse laser system using Yb doped laser ceramics for future laser application of generating high power tera-hertz wave for experimental proof of isotope separation and generating a Laser-Compton Scattering -ray source for precise specific isotopes analysis. As these future laser applications needs very stable and high average power laser system, we develop thin disk laser system using Yb:YAG ceramics because of its large stored energy property and large thermal conductivity, which could avoid thermal induced effects and thermal fracture limitation due to large pumping power. A few hundred m thickness of thin disk laser material in laser amplifier needs multi pass optical components for enough absorption of pump power, the pumping profile and spot size on laser disk should be variable for required laser performance. We design multi pass pumping module for thin disk laser material which consists of commercial optical components and precise stages and also design doublet and triplet for various pumping profile and spot size, the laser oscillation power is evaluated with this pumping module.

Yb:YAG thin-disk chirped pulse amplification laser system for intense terahertz pulse generation

Ochi, Yoshihiro; Nagashima, Keisuke; Maruyama, Momoko; Tsubouchi, Masaaki; Yoshida, Fumiko; Kono, Nanase; Mori, Michiaki; Sugiyama, Akira

Optics Express (Internet), 23(11), p.15057 - 15064, 2015/06

https://doi.org/10.1364/OE.23.015057

We have developed a 1 kHz repetition picosecond laser system dedicated for intense terahertz (THz) pulse generation. The system comprises a chirped pulse amplification laser equipped with a Yb:YAG thin-disk amplifier. At room temperature, the Yb:YAG thin-disk regenerative amplifier provides pulses having energy of over 10 mJ and spectral bandwidth of 1.2 nm. The pulse duration achieved after passage through a diffraction grating pair compressor was 1.3 ps. By employing this picosecond laser as a pump source, THz pulses having a peak frequency of 0.3 THz and 4 J of energy were generated by means of optical rectification in an Mg-doped LiNbO crystal.

Contact grating device with Fabry-Perot resonator for effective terahertz light generation

Tsubouchi, Masaaki; Nagashima, Keisuke; Yoshida, Fumiko; Ochi, Yoshihiro; Maruyama, Momoko

Optics Letters, 39(18), p.5439 - 5442, 2014/09

https://doi.org/10.1364/OL.39.005439

A novel design for a contact grating device with an incorporated Fabry-Perot resonator is proposed for high-power terahertz light (THz) generation. We deposited a multilayer consisting of TaO and AlO on a magnesium-doped stoichiometric LiNbO substrate and fabricated grating grooves on the outermost layer. The multilayer was designed such that conditions for a Fabry-Perot resonator were satisfied for light diffracted by the grating. Consequently, the fraction of light transmitted into the LiNbO substrate, i.e., the diffraction efficiency, was enhanced by the resonator. The diffraction efficiency of the fabricated device was 71%, which is close to the calculated value of 78% from the optimized design. THz light generation was also demonstrated with the contact grating device. The THz output of 0.41 microJ was obtained using NIR pump light of 2.7 mJ.

Picosecond snapshot of the speckles from ferroelectric BaTiO by means of X-ray lasers

Tai, R.; Namikawa, Kazumichi*; Kishimoto, Maki; Tanaka, Momoko; Sukegawa, Kota*; Hasegawa, Noboru; Kawachi, Tetsuya; Kado, Masataka; Lu, P.; Nagashima, Keisuke; et al.

Physical Review Letters, 89(25), p.257602_1 - 267602_4, 2002/12

https://doi.org/10.1103/PhysRevLett.89.257602

no abstracts in English

Development of intense THz light for control of molecules

Tsubouchi, Masaaki; Ochi, Yoshihiro; Maruyama, Momoko; Yoshida, Fumiko; Nagashima, Keisuke

no journal, , 

The nonlinear interaction between terahertz (THz) light and matter has recently been of interest for its availability to control molecular alignment in space. The pulse train of the intense THz light is one of the candidates to align the molecules efficiently and nondestructively. In this study, we have developed the experimental apparatus to generate the intense THz light. The THz etalon to generate the THz pulse train has been presented in our previous study.

Progress and prospects of coherent X-ray research using high power lasers in JAEA

Kawachi, Tetsuya; Nishikino, Masaharu; Sasaki, Akira; Ishino, Masahiko; Hasegawa, Noboru; Imazono, Takashi; Pikuz, T.; Faenov, A. Ya.*; Magnitskiy, S.*; Maruyama, Momoko; et al.

no journal, , 

Laser-driven X-ray sources are widely used in probing substances for new material development etc. Besides the laser-driven sources have potentials to downsizing and ultra-short duration, we carry out the coherent X-ray research, i.e., soft X-ray lasers and higher order harmonics generation (HHG) and their applications. In the source study, the first observation of X-ray mirage and HHG from relativistic plasma are presented. In the applications, we show the surface dynamics of fs laser ablation of metal observed by the X-ray interferometer. Finally we mention the prospects for the future: By the financial support from government, we started upgrade of J-KAREN laser toward PW level to realize keV coherent X-ray and high energy particle beams. By use of this high peak power laser and another high average power lasers, we will explore the possibility of ultra-short-duration short-wavelength lasers and open up new applications of high average power coherent X-rays.

Source development and novel applications of coherent X-rays and energetic particle beams using high peak power lasers in Japan Atomic Energy Agency

Kawachi, Tetsuya; Nishikino, Masaharu; Faenov, A.*; Pikuz, T.*; Ishino, Masahiko; Hasegawa, Noboru; Magnitskiy, S.*; Pirozhkov, A. S.; Esirkepov, T. Z.; Nishiuchi, Mamiko; et al.

no journal, , 

Laser-driven particle and radiation sources have unique and attractive characteristics such as ultra-short duration, high peak brilliance and potentials of downsizing of the source etc. Recent advent of high peak power lasers toward peta-watt (PW) level makes it possible for us to realize these particle and radiation sources with higher energy region, and now we are on the stage to investigate the mechanisms in detail and to start the applications of these novel sources. In this presentation, first of all, recent research activities in major high peak power laser facilities in Japan will be introduced, and then we will present research highlights in the last few years on the source development and the applications using high peak power lasers in Japan Atomic Energy Agency (JAEA) based upon Japan-Russia collaborations.

Contact grating device with Fabry-Perot resonator for effective THz light generation

Tsubouchi, Masaaki; Nagashima, Keisuke; Yoshida, Fumiko; Ochi, Yoshihiro; Maruyama, Momoko

no journal, , 

A novel design for a contact grating device with an incorporated Fabry-Perot resonator is proposed for high-power terahertz light (THz) generation. We deposited a multilayer consisting of TaO and AlO on a magnesium-doped stoichiometric LiNbO substrate and fabricated grating grooves on the outermost layer. The multilayer was designed such that conditions for a Fabry-Perot resonator were satisfied for light diffracted by the grating. Consequently, the fraction of light transmitted into the LiNbO substrate, i.e., the diffraction efficiency, was enhanced by the resonator. The diffraction efficiency of the fabricated device was 71%, which is close to the calculated value of 78% from the optimized design. THz light generation was also demonstrated with the contact grating device. The THz output of 0.41 uJ was obtained using NIR pump light of 2.7 mJ.

Contact grating device with Fabry-Perot resonator for effective THz light generation

Tsubouchi, Masaaki; Nagashima, Keisuke; Yoshida, Fumiko; Ochi, Yoshihiro; Maruyama, Momoko

no journal, , 

A novel design for a contact grating device with an incorporated Fabry-Perot resonator is proposed for high-power terahertz light (THz) generation. We deposited a multilayer consisting of TaO and AlO on a magnesium-doped stoichiometric LiNbO substrate and fabricated grating grooves on the outermost layer. The multilayer was designed such that conditions for a Fabry-Perot resonator were satisfied for light diffracted by the grating. Consequently, the fraction of light transmitted into the LiNbO substrate, i.e., the diffraction efficiency, was enhanced by the resonator. The diffraction efficiency of the fabricated device was 71%, which is close to the calculated value of 78% from the optimized design. THz light generation was also demonstrated with the contact grating device. The THz output of 410 nJ was obtained using NIR pump light of 2.7 mJ.