Journals >High Power Laser Science and Engineering
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2023
Volume: 11 Issue 1
14 Article(s)
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Research Articles
High temporal contrast 1053 nm laser source based on optical parametric amplification and second-harmonic generation
Liya Shen, Yanyan Li, Wenkai Li, Jiajun Song, Junyu Qian, Jianyu Sun, Renyu Feng, Yujie Peng, and Yuxin Leng
Temporal contrast directly affects the interaction between ultraintense and ultrashort pulse lasers with matter. Seed laser sources with broad bandwidth and high temporal contrast are significant for overall temporal contrast enhancement. The technique of cascaded nonlinear processes with optical parametric amplificatiTemporal contrast directly affects the interaction between ultraintense and ultrashort pulse lasers with matter. Seed laser sources with broad bandwidth and high temporal contrast are significant for overall temporal contrast enhancement. The technique of cascaded nonlinear processes with optical parametric amplification and second-harmonic generation is demonstrated for high temporal contrast seed source generation. Within 40 ps before the main pulse, the temporal contrast reaches over 1011. The pulse energy and duration of the high-contrast pulse are 112 μJ and 70 fs, respectively. Considering its high beam quality and stability, this laser source can serve as a high-quality seed for Nd:glass-based ultraintense and ultrashort pulse laser facilities..
High Power Laser Science and Engineering
- Publication Date: Jan. 25, 2023
- Vol. 11, Issue 1, 010000e1 (2023)
Demonstration of a petawatt-scale optical parametric chirped pulse amplifier based on yttrium calcium oxyborate
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, and Jianqiang Zhu
As optical parametric chirped pulse amplification has been widely adopted for the generation of extreme intensity laser sources, nonlinear crystals of large aperture are demanded for high-energy amplifiers. Yttrium calcium oxyborate (YCa4O(BO3)3, YCOB) is capable of being grown with apertures exceeding 100 mm, which maAs optical parametric chirped pulse amplification has been widely adopted for the generation of extreme intensity laser sources, nonlinear crystals of large aperture are demanded for high-energy amplifiers. Yttrium calcium oxyborate (YCa4O(BO3)3, YCOB) is capable of being grown with apertures exceeding 100 mm, which makes it possible for application in systems of petawatt scale. In this paper, we experimentally demonstrated for the first time to our knowledge, an ultra-broadband non-collinear optical parametric amplifier with YCOB for petawatt-scale compressed pulse generation at 800 nm. Based on the SG-II 5 PW facility, amplified signal energy of approximately 40 J was achieved and pump-to-signal conversion efficiency was up to 42.3%. A gain bandwidth of 87 nm was realized and supported a compressed pulse duration of 22.3 fs. The near-field and wavefront aberration represented excellent characteristics, which were comparable with those achieved in lithium triborate-based amplifiers. These results verified the great potential for YCOB utilization in the future..
High Power Laser Science and Engineering
- Publication Date: Jan. 23, 2023
- Vol. 11, Issue 1, 010000e2 (2023)
High-power 1560 nm single-frequency erbium fiber amplifier core-pumped at 1480 nm
Xin Cheng, Zhiquan Lin, Xuezong Yang, Shuizhen Cui, Xin Zeng, Huawei Jiang, and Yan Feng
High-power continuous-wave single-frequency Er-doped fiber amplifiers at 1560 nm by in-band and core pumping of a 1480 nm Raman fiber laser are investigated in detail. Both co- and counter-pumping configurations are studied experimentally. Up to 59.1 W output and 90% efficiency were obtained in the fundamental mode andHigh-power continuous-wave single-frequency Er-doped fiber amplifiers at 1560 nm by in-band and core pumping of a 1480 nm Raman fiber laser are investigated in detail. Both co- and counter-pumping configurations are studied experimentally. Up to 59.1 W output and 90% efficiency were obtained in the fundamental mode and linear polarization in the co-pumped case, while less power and efficiency were achieved in the counter-pumped setup for additional loss. The amplifier performs indistinguishably in terms of laser linewidth and relative intensity noise in the frequency range up to 10 MHz for both configurations. However, the spectral pedestal is raised in co-pumping, caused by cross-phase modulation between the pump and signal laser, which is observed and analyzed for the first time. Nevertheless, the spectral pedestal is 34.9 dB below the peak, which has a negligible effect for most applications..
High Power Laser Science and Engineering
- Publication Date: Jan. 17, 2023
- Vol. 11, Issue 1, 010000e3 (2023)
A 100-PW compressor based on single-pass single-grating pair
Shuman Du, Xiong Shen, Wenhai Liang, Peng Wang, Jun Liu, and Ruxin Li
A multistep pulse compressor (MPC) based on a single-pass single-grating pair (SSGP) is proposed to simplify the entire multi-petawatt (PW) compressor. Only one grating pair with relatively long perpendicular distance is used to generate the same amount of spectral chirp compared with a four-grating main compressor. AsA multistep pulse compressor (MPC) based on a single-pass single-grating pair (SSGP) is proposed to simplify the entire multi-petawatt (PW) compressor. Only one grating pair with relatively long perpendicular distance is used to generate the same amount of spectral chirp compared with a four-grating main compressor. As SSGP compressor induces the largest spatial chirp, it can introduce the best beam-smoothing effect to the laser beam on the last grating. When considering the diffraction loss of only two gratings, the total compression efficiency of the SSGP compressor is even larger than that of a four-grating main compressor. Furthermore, the wavefront aberration induced by the SSGP compressor can be better compensated by using deformable mirrors; however, it is difficult or complicated to be well compensated in a four-grating compressor. Approximately 50–100 PW laser pulses can be obtained using this SSGP-based multistage-smoothing MPC with a single laser beam..
High Power Laser Science and Engineering
- Publication Date: Jan. 13, 2023
- Vol. 11, Issue 1, 010000e4 (2023)
Ultra-broadband pulse generation via hollow-core fiber compression and frequency doubling for ultra-intense lasers
Yanyan Li, Beijie Shao, Yujie Peng, Junyu Qian, Wenkai Li, Xinliang Wang, Xingyan Liu, Xiaoming Lu, Yi Xu, Yuxin Leng, and Ruxin Li
We demonstrate an ultra-broadband high temporal contrast infrared laser source based on cascaded optical parametric amplification, hollow-core fiber (HCF) and second harmonic generation processes. In this setup, the spectrum of an approximately 1.8 μm laser pulse has near 1 μm full bandwidth by employing an argon gas-fWe demonstrate an ultra-broadband high temporal contrast infrared laser source based on cascaded optical parametric amplification, hollow-core fiber (HCF) and second harmonic generation processes. In this setup, the spectrum of an approximately 1.8 μm laser pulse has near 1 μm full bandwidth by employing an argon gas-filled HCF. Subsequently, after frequency doubling with cascaded crystals and dispersion compensation by a fused silica wedge pair, 9.6 fs (~3 cycles) and 150 μJ pulses centered at 910 nm with full bandwidth of over 300 nm can be generated. The energy stability of the output laser pulse is excellent with 0.8% (root mean square) over 20 min, and the temporal contrast is >1012 at –10 ps before the main pulse. The excellent temporal and spatial characteristics and stability make this laser able to be used as a good seed source for ultra-intense and ultrafast laser systems..
High Power Laser Science and Engineering
- Publication Date: Jan. 11, 2023
- Vol. 11, Issue 1, 010000e5 (2023)
Diode-pumped high-power continuous-wave intracavity frequency-doubled Pr3+:YLF ultraviolet lasers around 349 nm
Xiuji Lin, Zheng Zhang, Shuaihao Ji, Run Fang, Bo Xiao, Huiying Xu, and Zhiping Cai
High-power continuous-wave ultraviolet lasers are useful for many applications. As ultraviolet laser sources, the wavelength switching capability and compact structure are very important to extend the applicability and improve the flexibility in practical applications. In this work, we present two simple and relativelyHigh-power continuous-wave ultraviolet lasers are useful for many applications. As ultraviolet laser sources, the wavelength switching capability and compact structure are very important to extend the applicability and improve the flexibility in practical applications. In this work, we present two simple and relatively compact schemes by laser diode pumping to obtain a watt-level single-wavelength 348.7-nm laser and discrete wavelength tunable ultraviolet lasers around 349 nm (from 334.7 to 364.5 nm) by intracavity frequency doubling based on Pr3+:YLF and $\unicode{x3b2}$ -BBO crystals. The maximum output power of the single-wavelength 348.7-nm laser is 1.033 W. The output powers of the discrete wavelength tunable lasers are at the level of tens of milliwatts, except for two peaks at 348.7 and 360.3 nm with output powers of approximately 500 mW. In addition, simulations are carried out to explain the experimental results and clarify the tuning mechanisms..
High Power Laser Science and Engineering
- Publication Date: Dec. 05, 2022
- Vol. 11, Issue 1, 010000e6 (2023)
Applications of object detection networks in high-power laser systems and experiments | On the Cover
Jinpu Lin, Florian Haberstroh, Stefan Karsch, and Andreas Döpp
The recent advent of deep artificial neural networks has resulted in a dramatic increase in performance for object classification and detection. While pre-trained with everyday objects, we find that a state-of-the-art object detection architecture can very efficiently be fine-tuned to work on a variety of object detectThe recent advent of deep artificial neural networks has resulted in a dramatic increase in performance for object classification and detection. While pre-trained with everyday objects, we find that a state-of-the-art object detection architecture can very efficiently be fine-tuned to work on a variety of object detection tasks in a high-power laser laboratory. In this paper, three exemplary applications are presented. We show that the plasma waves in a laser–plasma accelerator can be detected and located on the optical shadowgrams. The plasma wavelength and plasma density are estimated accordingly. Furthermore, we present the detection of all the peaks in an electron energy spectrum of the accelerated electron beam, and the beam charge of each peak is estimated accordingly. Lastly, we demonstrate the detection of optical damage in a high-power laser system. The reliability of the object detector is demonstrated over 1000 laser shots in each application. Our study shows that deep object detection networks are suitable to assist online and offline experimental analysis, even with small training sets. We believe that the presented methodology is adaptable yet robust, and we encourage further applications in Hz-level or kHz-level high-power laser facilities regarding the control and diagnostic tools, especially for those involving image data..
High Power Laser Science and Engineering
- Publication Date: Jan. 13, 2023
- Vol. 11, Issue 1, 010000e7 (2023)
High-performance 800–1050 nm seed pulses based on spectral broadening and filtering for petawatt lasers
Wenhai Liang, Renjing Chen, Yilin Xu, Yaping Xuan, Peng Wang, Jun Liu, and Ruxin Li
High-performance 86 μJ, 11.2 fs pulses with a spectrum range of 800–1050 nm are generated based on 1030 nm, 190 fs Yb femtosecond pulses by using multi-plate-based spectral broadening and filtering. Taking advantage of single beam configuration, the obtained pulses have excellent power and spectral stabilities. Since tHigh-performance 86 μJ, 11.2 fs pulses with a spectrum range of 800–1050 nm are generated based on 1030 nm, 190 fs Yb femtosecond pulses by using multi-plate-based spectral broadening and filtering. Taking advantage of single beam configuration, the obtained pulses have excellent power and spectral stabilities. Since the output spectrum is obtained by spectrally filtering the broadened components, the temporal contrast of the output pulses is enhanced by at least four orders of magnitude. Together with the robust and simple setup, the proposed method is expected to be a competitive option for the generation of seed pulses for 10s–100s petawatt lasers..
High Power Laser Science and Engineering
- Publication Date: Jan. 06, 2023
- Vol. 11, Issue 1, 010000e8 (2023)
Laser wakefield accelerator modelling with variational neural networks | Editors' Pick
M. J. V. Streeter, C. Colgan, C. C. Cobo, C. Arran, E. E. Los, R. Watt, N. Bourgeois, L. Calvin, J. Carderelli, N. Cavanagh, S. J. D. Dann, R. Fitzgarrald, E. Gerstmayr, A. S. Joglekar, B. Kettle, P. Mckenna, C. D. Murphy, Z. Najmudin, P. Parsons, Q. Qian, P. P. Rajeev, C. P. Ridgers, D. R. Symes, A. G. R. Thomas, G. Sarri, and S. P. D. Mangles
A machine learning model was created to predict the electron spectrum generated by a GeV-class laser wakefield accelerator. The model was constructed from variational convolutional neural networks, which mapped the results of secondary laser and plasma diagnostics to the generated electron spectrum. An ensemble of traiA machine learning model was created to predict the electron spectrum generated by a GeV-class laser wakefield accelerator. The model was constructed from variational convolutional neural networks, which mapped the results of secondary laser and plasma diagnostics to the generated electron spectrum. An ensemble of trained networks was used to predict the electron spectrum and to provide an estimation of the uncertainty of that prediction. It is anticipated that this approach will be useful for inferring the electron spectrum prior to undergoing any process that can alter or destroy the beam. In addition, the model provides insight into the scaling of electron beam properties due to stochastic fluctuations in the laser energy and plasma electron density..
High Power Laser Science and Engineering
- Publication Date: Jan. 06, 2023
- Vol. 11, Issue 1, 010000e9 (2023)
A 110 W fiber gas Raman laser at 1153 nm
Yulong Cui, Xin Tian, Binyu Rao, Hao Li, Wei Huang, Wenxi Pei, Meng Wang, Zilun Chen, and Zefeng Wang
We report here the first hundred-watt continuous wave fiber gas laser in H2-filled hollow-core photonic crystal fiber (PCF) by stimulated Raman scattering. The pump source is a homemade narrow-linewidth fiber oscillator with a 3 dB linewidth of 0.15 nm at the maximum output power of 380 W. To efficiently and stably couWe report here the first hundred-watt continuous wave fiber gas laser in H2-filled hollow-core photonic crystal fiber (PCF) by stimulated Raman scattering. The pump source is a homemade narrow-linewidth fiber oscillator with a 3 dB linewidth of 0.15 nm at the maximum output power of 380 W. To efficiently and stably couple several-hundred-watt pump power into the hollow core and seal the gas, a hollow-core fiber end-cap is fabricated and used at the input end. A maximum power of 110 W at 1153 nm is obtained in a 5 m long hollow-core PCF filled with 36 bar H2, and the conversion efficiency of the first Stokes power is around 48.9%. This work paves the way for high-power fiber gas Raman lasers..
High Power Laser Science and Engineering
- Publication Date: Feb. 28, 2023
- Vol. 11, Issue 1, 01000e10 (2023)
High-peak-power random Yb-fiber laser with intracavity Raman-frequency comb generation
Xinxing Liu, Wenhui Hao, Zhihui Yang, and Yulong Tang
The random fiber laser (RFL) has been an excellent platform for exploring novel optical dynamics and developing new functional optoelectronic devices. However, it is challenging for RFLs to regulate their emission into regular narrow pulses due to their intrinsic randomness. Here, through engineering the laser configurThe random fiber laser (RFL) has been an excellent platform for exploring novel optical dynamics and developing new functional optoelectronic devices. However, it is challenging for RFLs to regulate their emission into regular narrow pulses due to their intrinsic randomness. Here, through engineering the laser configuration (cavity Q value, gain distribution and nonlinearity), we demonstrate that narrow (~2.5 ns) pulses with record peak power as high as 64.3 kW are achieved from a self-Q-switched random ytterbium fiber laser. Based on high intracavity intensity and efficient interplay of multiple nonlinear processes (stimulated Brillouin scattering, stimulated Raman scattering and four-wave mixing), an over-one-octave visible-near-infrared (NIR) Raman-frequency comb is generated from single-mode silica fibers for the first time. After spectrally filtering the Raman peaks, wavelength-tunable pulses with durations of several hundreds of picoseconds are obtained. Such a high-peak-power random Q-switched fiber laser and wide frequency comb in the visible-NIR region can find applications in diverse areas, such as spectroscopy, biomedical imaging and quantum information..
High Power Laser Science and Engineering
- Publication Date: Dec. 15, 2022
- Vol. 11, Issue 1, 01000e11 (2023)
2.1 μm, high-energy dissipative soliton resonance from a holmium-doped fiber laser system
Desheng Zhao, Bin Zhang, Xiran Zhu, Shuailin Liu, Li Jiang, Zhiyuan Dou, Linyong Yang, and Jing Hou
We propose a 2.1 μm high-energy dissipative soliton resonant (DSR) fiber laser system based on a mode-locked seed laser and dual-stage amplifiers. In the seed laser, the nonlinear amplifying loop mirror technique is employed to realize mode-locking. The utilization of an in-band pump scheme and long gain fiber e
We propose a 2.1 μm high-energy dissipative soliton resonant (DSR) fiber laser system based on a mode-locked seed laser and dual-stage amplifiers. In the seed laser, the nonlinear amplifying loop mirror technique is employed to realize mode-locking. The utilization of an in-band pump scheme and long gain fiber enables effectively exciting 2.1 μm pulses. A section of ultra-high numerical aperture fiber (UHNAF) with normal dispersion and high nonlinearity and an output coupler with a large coupling ratio are used to achieve a high-energy DSR system. By optimizing the UHNAF length to 55 m, a 2103.7 nm, 88.1 nJ DSR laser with a 3-dB spectral bandwidth of 0.48 nm and a pulse width of 17.1 ns is obtained under a proper intracavity polarization state and pump power. The output power and conversion efficiency are 0.233 W and 4.57%, respectively, both an order of magnitude higher than those of previously reported holmium-doped DSR seed lasers. Thanks to the high output power and nanosecond pulse width of the seed laser, the average power of the DSR laser is linearly scaled up to 50.4 W via a dual-stage master oscillator power amplifier system. The 3-dB spectral bandwidth broadens slightly to 0.52 nm, and no distortion occurs in the amplified pulse waveform. The corresponding pulse energy reaches 19.1 μJ, which is the highest pulse energy in a holmium-doped mode-locked fiber laser system to the best of our knowledge. Such a 2.1 μm, high-energy DSR laser with relatively wide pulse width has prospective applications in mid-infrared nonlinear frequency conversion.
.High Power Laser Science and Engineering
- Publication Date: Jan. 17, 2023
- Vol. 11, Issue 1, 01000e12 (2023)
Angle amplifier in a 2D beam scanning system based on peristrophic multiplexed volume Bragg gratings
Yuanzhi Dong, Yunxia Jin, Fanyu Kong, Jingyin Zhao, Jianwei Mo, Dongbing He, Jing Sun, and Jianda Shao
In this paper, a 2D angle amplifier based on peristrophic multiplexed volume Bragg gratings is designed and prepared, in which a calculation method is firstly proposed to optimize the number of channels to a minimum. The induction of peristrophic multiplexing reduces the performance difference in one bulk of the gratinIn this paper, a 2D angle amplifier based on peristrophic multiplexed volume Bragg gratings is designed and prepared, in which a calculation method is firstly proposed to optimize the number of channels to a minimum. The induction of peristrophic multiplexing reduces the performance difference in one bulk of the grating, whereas there is no need to deliberately optimize the fabrication process. It is revealed that a discrete 2D angle deflection range of ±30° is obtained and the relative diffraction efficiency of all the grating channels reaches more than 55% with a root-mean-square deviation of less than 3.4% in the same grating. The deviation of the Bragg incidence and exit angles from the expected values is less than 0.07°. It is believed that the proposed 2D angle amplifier has the potential to realize high-performance and large-angle beam steering in high-power laser beam scanning systems..
High Power Laser Science and Engineering
- Publication Date: Jan. 05, 2023
- Vol. 11, Issue 1, 01000e13 (2023)
Short mid-infrared watt-level all-fiber nonlinear pulse compressor above 100-MHz pulse repetition rate
Jingcheng Shang, Chao Mei, Shengzhi Zhao, Yizhou Liu, Kejian Yang, Chun Wang, Tao Li, and Tianli Feng
We firstly report a 2-μm all-fiber nonlinear pulse compressor based on two pieces of normal dispersion fiber (NDF), which enables a high-power scaling ability of watt-level and a high pulse compression ratio of 13.7. With the NDF-based all-fiber nonlinear pulse compressor, the 450-fs laser pulses with a repetition rateWe firstly report a 2-μm all-fiber nonlinear pulse compressor based on two pieces of normal dispersion fiber (NDF), which enables a high-power scaling ability of watt-level and a high pulse compression ratio of 13.7. With the NDF-based all-fiber nonlinear pulse compressor, the 450-fs laser pulses with a repetition rate of 101.4 MHz are compressed to 35.1 fs, corresponding to a 5.2 optical oscillation cycle at the 2-μm wavelength region. The output average power reaches 1.28 W, which is believed to be the highest value never achieved from the previous 2-μm all-fiber nonlinear pulse compressors with a high pulse repetition rate above 100 MHz. The dynamic evolution of the ultrafast pulse inside the all-fiber nonlinear pulse compressor is numerically analyzed, matching well with the experimental results..
High Power Laser Science and Engineering
- Publication Date: Dec. 23, 2022
- Vol. 11, Issue 1, 01000e14 (2023)
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