Article
Optics
Jiabing Hu, Xinliang Wang, Yi Xu, Lianghong Yu, Fenxiang Wu, Zongxin Zhang, Xiaojun Yang, Penghua Ji, Peile Bai, Xiaoyan Liang, Yuxin Leng, Ruxin Li
Summary: This work presents a comprehensive numerical investigation on a high-energy OPCPA based on a large-aperture DKDP crystal. The analysis includes the effects of deuteration level, absorption loss, temperature variation, and optimization of zero-phase-mismatch wavelength on the efficiency-bandwidth product. The study shows that broadband and high-efficiency amplification can be achieved in the DKDP crystal with moderate deuteration level by optimizing the zero-phase-mismatch wavelength.
Article
Optics
Peter Fischer, Alexander Muschet, Tino Lang, Roushdey Salh, Laszlo Veisz
Summary: Optical Parametric Chirped-Pulse Amplification (OPCPA) is a light amplification technique that supports few-cycle pulses with multi-terawatt peak powers by providing broad spectral gain bandwidth and large energy. Controlling saturation in OPCPA can significantly improve overall gain, conversion efficiency, and spectral bandwidth.
Article
Optics
Takashi Sakamoto, Kosuke Yoshioka
Summary: The chirped pulse amplification of a 1.6 GHz Ti:sapphire femto-second frequency comb was successfully achieved using a GaAs-based tapered semiconductor amplifier. The amplified spectral component reached a peak power of 1.48 kW and an average power of 150 mu W per mode. The competition between amplified spontaneous emission and coherent signal was observed at high driving currents, with a numerical analysis presented to explain the gain suppression. This amplification method is valuable for high repetition rate frequency combs with a wider spectral range.
Article
Optics
Yannik Zobus, Christian Brabetz, Markus Loeser, Daniel Albach, Mathias Siebold, Vincent Bagnoud
Summary: We have developed a pump system for ultrafast optical parametric amplifiers (uOPA) as an upgrade for existing uOPA at PHELIX and the new PENELOPE. The system consists of a two-stage chirped pulse amplifier, centered around a high energy Yb:YAG regenerative amplifier, with high beam quality and relative energy stability. It achieves efficient second harmonic generation and a high pulse energy at 515 nm. It is a widely applicable and self-seedable pump module for uOPA.
Article
Optics
S. Bucht, R. G. Roides, B. Webb, D. Haberberger, C. Feng, D. H. Froula, J. Bromage
Summary: Optical parametric chirped-pulse amplification generates two broadband pulses, a signal and an idler, with peak powers >100 GW. While the signal is usually used, compressing the longer-wavelength idler allows for experiments where the driving laser wavelength is crucial. This paper discusses the addition of subsystems to address angular dispersion and spectral phase reversal issues introduced by the idler in a petawatt class optical parametric amplifier line.
Article
Optics
Yirui Wang, Jing Wang, Jingui Ma, Peng Yuan, Liejia Qian
Summary: This paper reveals that spatial chirp distortion can be significantly mitigated in quasi-parametric chirped-pulse amplification (QPCPA) with idler absorption, leading to improved quality of focused intensity.
HIGH POWER LASER SCIENCE AND ENGINEERING
(2022)
Article
Optics
Simon Roeder, Yannik Zobus, Christian Brabetz, Vincent Bagnoud
Summary: In this study, we propose and experimentally verify a model that explains the combined influence of beam size and optical roughness on the temporal contrast of optical pulses passing through a pulse stretcher. By comparing experimental results with an analytical model, we find that different beam sizes have different effects on the temporal contrast.
HIGH POWER LASER SCIENCE AND ENGINEERING
(2022)
Article
Optics
Timo Eichner, Thomas Hulsenbusch, Julian Dirkwinkel, Tino Lang, Lutz Winkelmann, Guido Palmer, Andreas R. Maier
Summary: This article presents a seed laser with high beam quality and energy stability based on collinear optical parametric chirped pulse amplification (OPCPA) technology. Through experimental and simulation studies, the authors found that saturation of the OPCPA stage leads to a degradation of the beam quality, but the spectral homogeneity of the beam quality can be greatly improved by removing specific spatial frequencies.
Article
Optics
Fenxiang Wu, Xingyan Liu, Xinliang Wang, Jiabing Hu, Xiaoming Lu, Yanyan Li, Yujie Peng, Yanqi Liu, Junchi Chen, Yingbin Long, Wenkai Li, Zongxin Zhang, Yi Xu, Cheng Wang, Yuxin Leng, Ruxin Li
Summary: The feasibility of dispersion control in OPCPA systems using the double-grating Offner stretcher has been demonstrated, achieving compression of near FTL pulses, making it an ideal pulse stretcher.
OPTICS AND LASER TECHNOLOGY
(2022)
Article
Optics
Meizhi Sun, Jun Kang, Xiao Liang, Haidong Zhu, Qingwei Yang, Qi Gao, Ailin Guo, Ping Zhu, Panzheng Zhang, Linjun Li, Lijuan Qiu, Zhantao Lu, Sheng Wang, Xiaoniu Tu, Xinglong Xie, Jianqiang Zhu
Summary: In this paper, we demonstrated for the first time an ultra-broadband non-collinear optical parametric amplifier with YCOB for petawatt-scale compressed pulse generation at 800 nm. The experiment achieved an amplified signal energy of approximately 40 J with a pump-to-signal conversion efficiency of 42.3% and a gain bandwidth of 87 nm, supporting a compressed pulse duration of 22.3 fs. The results confirmed the great potential for the utilization of YCOB in the future.
HIGH POWER LASER SCIENCE AND ENGINEERING
(2023)
Article
Optics
Keyang Liu, Yanqi Liu, Yunhai Tang, Junchi Chen, Cheng Wang, Xingyan Liu, Yingbin Long, Yi Xu, Yujie Peng, Xiaoming Lu, Zhengzheng Liu, Yuxin Leng, Xiaobin Wang
Summary: A novel tiled Ti:sapphire amplifier was demonstrated with >1 J amplified chirped pulse output, achieving a maximum peak power of 28 TW and energy conversion efficiency comparable to that of a single Ti:S amplifier. This technique may provide a potential pathway for 100 PW or EW lasers in the future.
CHINESE OPTICS LETTERS
(2021)
Article
Optics
Yufang Ding, Jinsheng Liu, Xingbin Gu, Peng Yuan, Jingui Ma
Summary: We demonstrate highly efficient mid-infrared quasi-parametric chirped-pulse amplification (QPCPA) using a Sm3+-doped La3Ga5.5Nb0.5O14 (Sm:LGN) crystal. With pump wavelength at 1 μm, Sm3+ broadband absorption enables QPCPA for femtosecond signal pulses at 3.5 or 5 μm with near quantum-limited conversion efficiency. The mid-infrared QPCPA based on Sm:LGN exhibits robustness against phase-mismatch and pump-intensity variation due to back conversion suppression. This approach efficiently converts intense laser pulses at 1 μm into mid-infrared ultrashort pulses.
Article
Optics
J. Bromage, S-W Bahk, M. Bedzyk, I. A. Begishev, S. Bucht, C. Dorrer, C. Feng, C. Jeon, C. Mileham, R. G. Roides, K. Shaughnessy, M. J. I. I. I. I. I. I. Shoup, M. Spilatro, B. Webb, D. Weiner, J. D. Zuegel
Summary: Optical parametric chirped-pulse amplification using multikilojoule Nd:glass pump lasers is a promising method for generating ultra-intense laser pulses. The MTW-OPAL Laser System is a mid-scale prototype aimed at producing 0.5-PW pulses with technologies scalable to tens of petawatts. Campaigns completed since March 2020 show that the laser design is fundamentally sound, with ongoing optimization for future first-focus campaigns.
HIGH POWER LASER SCIENCE AND ENGINEERING
(2021)
Review
Optics
Audrius Dubietis, Aidas Matijosius
Summary: The generation of power- and wavelength-scalable few optical cycle pulses is a major challenge in laser physics. Table-top optical parametric chirped pulse amplification-based systems have made significant progress in the past decade, achieving excellent performance characteristics in terms of pulse duration, energy, peak power, and repetition rate, making them at the forefront of modern ultrafast laser technology. These systems amplify octave-spanning spectra and produce carrier-envelope phase-stable, few optical cycle pulses with multi-gigawatt to multi-terawatt peak powers and multi-watt average powers, covering a wide range of the optical spectrum. This article provides a comprehensive overview of the state of the art in table-top optical parametric chirped pulse amplifiers, addressing scientific and technological aspects, and discussing potential practical applications in the field of ultrafast science.
OPTO-ELECTRONIC ADVANCES
(2023)
Article
Physics, Multidisciplinary
Rong Ye, Huining Dong, Xianyun Wu, Xiang Gao
Summary: A novel approach of phase matched broadband scanning optical parametric chirped pulse amplification (OPCPA) was proposed in this study, where the pump beam deflection enabled phase matching of each chirped signal frequency. Simulation results showed that this method could maintain the spectral distribution of chirped signal pulse almost unchanged.
Article
Physics, Applied
Kai Huang, Zhan Jin, Nobuhiko Nakanii, Tomonao Hosokai, Masaki Kando
Summary: This study investigates the jitter of electrons in laser wakefield acceleration. The relative arrival timings of the electron bunches were detected, and preliminary analysis suggests the duration of the electron bunches. The research demonstrates the potential of laser wakefield acceleration for femtosecond pump-probe studies.
APPLIED PHYSICS EXPRESS
(2022)
Article
Physics, Fluids & Plasmas
Hikari Ohiro, Alexander S. Pirozhkov, Koichi Ogura, Akito Sagisaka, Tatiana A. Pikuz, Kai Huang, Masaki Kando, Kotaro Yamasaki, Shinichi Namba
Summary: The Quantum Science and Technology Kansai group has discovered new harmonics X-ray radiation from relativistic laser-produced plasma, known as burst intensification by singularity emitting radiation (BISER). In this study, a magnetic bottle time-of-flight electron spectrometer was designed and constructed to characterize the BISER pulse width using a pump-probe method. The performance of the spectrometer was verified by measuring the electron spectra of xenon atoms irradiated with BISER X-rays. Experimental results showed the successful measurement of 8.26-eV Auger spectra associated with inner-shell electrons.
PLASMA AND FUSION RESEARCH
(2022)
Article
Multidisciplinary Sciences
Satoshi Jinno, Masato Kanasaki, Takafumi Asai, Ryutaro Matsui, Alexander S. Pirozhkov, Koichi Ogura, Akito Sagisaka, Yasuhiro Miyasaka, Nobuhiko Nakanii, Masaki Kando, Nobuko Kitagawa, Kunihiro Morishima, Satoshi Kodaira, Yasuaki Kishimoto, Tomoya Yamauchi, Mitsuru Uesaka, Hiromitsu Kiriyama, Yuji Fukuda
Summary: Multi-MeV high-purity proton acceleration has been achieved using a hydrogen cluster target irradiated with repetitive, relativistic intensity laser pulses. The spatial distribution of the accelerated protons is anisotropic, with higher energy protons preferentially accelerated along the laser propagation direction. The results suggest that laser-driven proton acceleration using micron-scale hydrogen clusters is promising for various applications.
SCIENTIFIC REPORTS
(2022)
Article
Physics, Applied
Nobuhiko Nakanii, Kai Huang, Kotaro Kondo, Hiromitsu Kiriyama, Masaki Kando
Summary: We have demonstrated the precise directional control of high-energy electron beams by moving a circular serrated aperture perpendicular to the laser propagation direction in a laser system. This technique is simple and effective as it allows for precise control of the electron beam direction without additional manipulation of the optics or gas target. It provides a valuable guideline for the future practical uses and development of laser-plasma accelerators.
APPLIED PHYSICS EXPRESS
(2023)
Article
Physics, Fluids & Plasmas
Yu-Hsin Chen, Antonio C. Ting, Bahman Hafizi, Michael H. Helle, Luke A. Johnson, Mikhail N. Polyanskiy, Igor V. Pogorelsky, Marcus Babzien, Nicholas P. Dover, Oliver C. Ettlinger, George S. Hicks, Emma-Jane Ditter, Zulfikar Najmudin, Daniel F. Gordon
Summary: We present the results of proton acceleration from hydrogen plasmas irradiated by intense CO2 laser, with the density gradient modified by Nd:YAG laser ablation-driven hydrodynamic shocks. The experimental results agree well with the simulations, but certain laser shots produced unexpectedly high proton energies. This might be attributed to nonlinear propagation effects and focusing of laser pulses through the plasma channel formed by preceding pulses.
PHYSICS OF PLASMAS
(2023)
Article
Instruments & Instrumentation
M. Koike, T. Hatano, A. S. Pirozhkov, Y. Ueno, M. Terauchi
Summary: Soft x-ray diffraction gratings coated with a supermirror-type multilayer were numerically optimized to enhance diffraction efficiency in the energy range of 2-4 keV. The optimized groove depth and incidence angle were determined to be 2.05 nm and 88.65 degrees, respectively, for a grating with a groove density of 3200 grooves/mm. The replacement of the top layer of W with Co, Cr, or Ni effectively improved the uniformity of diffraction efficiency, resulting in calculated diffraction efficiency of up to approximately 5.3% in the 2-4 keV range, almost eight times larger than that of an Au coated grating (approximately 0.7%).
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Optics
Nicholas P. P. Dover, Tim Ziegler, Stefan Assenbaum, Constantin Bernert, Stefan Bock, Florian-Emanuel Brack, Thomas E. E. Cowan, Emma J. J. Ditter, Marco Garten, Lennart Gaus, Ilja Goethel, George S. S. Hicks, Hiromitsu Kiriyama, Thomas Kluge, James K. K. Koga, Akira Kon, Kotaro Kondo, Stephan Kraft, Florian Kroll, Hazel F. F. Lowe, Josefine Metzkes-Ng, Tatsuhiko Miyatake, Zulfikar Najmudin, Thomas Pueschel, Martin Rehwald, Marvin Reimold, Hironao Sakaki, Hans-Peter Schlenvoigt, Keiichiro Shiokawa, Marvin E. P. Umlandt, Ulrich Schramm, Karl Zeil, Mamiko Nishiuchi
Summary: Laser-driven ion sources are a rapidly developing technology that can produce high energy, high peak current beams. In this study, we demonstrate the generation of high energy protons and carbon ions using sub-micrometer thickness Formvar foils irradiated with intense laser beams. The acceleration mechanism involves a rapid expulsion of electrons from the target bulk due to relativistically induced transparency. We replicate the mechanism on two different laser facilities and show that the optimum target thickness decreases with improved laser contrast.
LIGHT-SCIENCE & APPLICATIONS
(2023)
Article
Physics, Multidisciplinary
Zhenzhe Lei, Zhan Jin, Alexei Zhidkov, Naveen Pathak, Yoshio Mizuta, Kai Huang, Nobuhiki Nakanii, Izuru Daito, Masaki Kando, Tomonao Hosokai
Summary: Beam charge control is crucial in laser wakefield acceleration (LWFA) to develop high-energy electron accelerators. Precise control of charge in pre-accelerated electron bunches is necessary for practical electron beam characteristics in the final acceleration stage(s). The use of asymmetric gas-jet nozzles shows promise in developing charge control by tuning target parameters such as plasma density, density slope, and acceleration length.
PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS
(2023)
Article
Nanoscience & Nanotechnology
Tatsuhiko Miyatake, Sadaoki Kojima, Hironao Sakaki, Thanh-Hung Dinh, Ibuki Takemoto, Masayasu Hata, Masaharu Nishikino, Yukinobu Watanabe, Masahiko Ishino, Michiaki Mori, James Kevin Koga, Yoichi Yamamoto, Fuyumi Ito, Masaki Kando, Toshiyuki Shirai, Kiminori Kondo
Summary: The MTF characteristics of radiochromic film dosimetry with optical systems were evaluated using an RCF, HD-V2, and a resolution test chart. The evaluation showed that a high contrast spatial resolution with an MTF of >= 0.8 is limited to about 83.3 μm due to artifacts. To achieve higher contrast at higher frequencies, a test bench microdensitometer (TBMD) with a high contrast spatial resolution of about 11.9 μm was developed. The optical density error in the TBMD was found to increase with decreasing focal diameter, supporting the hypothesis of non-uniform shading and surface roughness in the HD-V2 active layer monomers.
Article
Optics
Hiromitsu Kiriyama, Yasuhiro Miyasaka, Akira Kon, Mamiko Nishiuchi, Akito Sagisaka, Hajime Sasao, Alexander S. Pirozhkov, Yuji Fukuda, Koichi Ogura, Kotaro Kondo, Nobuhiko Nakanii, Yuji Mashiba, Nicholas P. Dover, Liu Chang, Masaki Kando, Stefan Bock, Tim Ziegler, Thomas Pueschel, Hans-Peter Schlenvoigt, Karl Zeil, Ulrich Schramm
Summary: This paper describes the output performance and temporal quality enhancement of the J-KAREN-P petawatt laser facility, including wavefront correction, focusing, and investigation of technologies to improve the temporal contrast.
Article
Optics
Itsuki Nishibata, Nobuhiko Nakanii, Tomokazu Sano
Summary: The use of ultrashort pulse lasers above the air ionization threshold can cause detrimental focusing due to nonlinear optical phenomena. Changes in focusing characteristics in ultrashort pulse laser processing can reduce efficiency and quality. This study conducted numerical simulations to visualize focusing characteristics across pulse durations from femtoseconds to picoseconds. The distribution of fluence and the position of maximum focus are found to be dependent on pulse duration, and correction of irradiation position is crucial for proper processing. The achieved intensity and fluence under high numerical aperture conditions are determined by the combination of numerical aperture and pulse duration. These findings are vital for selecting optimal laser conditions and achieving optimal control of processing position in high-energy laser processing applications.
Article
Optics
Akira Kon, Mamiko Nishiuchi, Yuji Fukuda, Kotaro Kondo, Koichi Ogura, Akito Sagisaka, Yasuhiro Miyasaka, Nicholas P. Dover, Masaki Kando, Alexander S. Pirozhkov, Izuru Daito, Liu Chang, Il Woo Choi, Chang Hee Nam, Tim Ziegler, Hans-Peter Schlenvoigt, Karl Zeil, Ulrich Schramm, Hiromitsu Kiriyama
Summary: We present the design and characterization of a plasma mirror system installed on the J-KAREN-P laser. The system achieved a reflectivity exceeding 80% and improved temporal contrast by two orders of magnitude at 1 ps before the main pulse. Furthermore, the near-field spatial distribution of the laser remained constant with a plasma mirror fluence of less than 100 kJ/cm(2). We also investigated the differences and fluctuations in energy, pulse width, and pointing stability with and without the plasma mirror system.
HIGH POWER LASER SCIENCE AND ENGINEERING
(2022)
