Author Affiliations
Abstract
1 State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, China
2 School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
3 Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, China
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 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 temporal contrast nonlinear effect optical parametric amplification High Power Laser Science and Engineering
2023, 11(1): 010000e1
Author Affiliations
Abstract
1 State Key Laboratory of High Field Laser Physics and CAS Center for Excellence in Ultra-intense Laser Science, Shanghai Institute of Optics and Fine Mechanics (SIOM), Chinese Academy of Sciences (CAS), Shanghai, China
2 School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
3 Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, China
We demonstrate the simultaneous temporal contrast improvement and pulse compression of a Yb-doped femtosecond laser via nonlinear elliptical polarization rotation in a solid state multi-pass cell. The temporal contrast is improved to 109, while the pulse is shortened from 181 to 36 fs, corresponding to a compression factor of 5. The output beam features excellent beam quality with M2 values of 1.18 × 1.16. The total efficiency of the contrast enhancement system exceeds 50%. This technique will have wide applications in high temporal contrast ultra-intense femtosecond lasers.
multi-pass cell nonlinear elliptical polarization rotation pulse compression temporal contrast High Power Laser Science and Engineering
2022, 10(5): 05000e28
Author Affiliations
Abstract
1 School of Physics and Optoelectronic Engineering, Xidian University, Xi’an 710071, China
2 Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
3 University of Chinese Academy of Sciences, Beijing 100049, China
4 Songshan Lake Materials Laboratory, Dongguan 523808, China
5 CAS Center for Excellence in Ultra-intense Laser Science, Shanghai 201800, China
We report on a high-power diode-pumped (Yb:KGW) mode-locked laser with a semiconductor saturable absorber mirror (SESAM). For 32.7 W of incident pump power, we generate 261 fs pulses with the maximum average output power of up to 13.0 W and spectrum centered around 1039 nm at 68.4 MHz, corresponding to 190 nJ of single pulse energy and 0.72 MW of peak power. The optical-to-optical conversion efficiency is 39.8%, and the slope efficiency is 64.4%. The Yb:KGW laser exhibits a power stability better than 0.543% of the root-mean-square in 2 h.
ultrafast laser high-power femtosecond laser Yb:KGW crystal semiconductor saturable absorber mirror Chinese Optics Letters
2022, 20(2): 021404
Author Affiliations
Abstract
1 School of Physics and Optoelectronic Engineering, Xidian University, Xi’an710071, China
2 Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing100190, China
3 CAS Center for Excellence in Ultra-intense Laser Science, Shanghai201800, China
4 University of Chinese Academy of Sciences, Beijing100049, China
5 Songshan Lake Materials Laboratory, Dongguan523808, China
We demonstrate a diode-pumped femtosecond Yb:CaGdAlO4 (Yb:CALGO) laser with a semiconductor saturable absorber mirror (SESAM) for stable mode-locking operation. A perfect beam profile is measured under 10 W output power with $M_{x}^{2}$ = 1.017 and $M_{y}^{2}$ = 1.016 in the horizontal and vertical directions, respectively. At the repetition rate of 71.66 MHz, the optical pulse duration is 247 fs and the pulse energy is 140 nJ at the central wavelength of 1041 nm, corresponding to a peak power of 0.56 MW. In addition, we also generate continuous wave (CW) power of more than 15 W with TEM00 mode, corresponding to an optical-to-optical efficiency of 44.1%.
diode pump high power femtosecond oscillator passive mode-locking Yb:CALGO laser High Power Laser Science and Engineering
2021, 9(2): 02000e33
Author Affiliations
Abstract
1 Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
2 University of Chinese Academy of Sciences, Beijing 100049, China
3 School of Physics and Optoelectronic Engineering, Xidian University, Xi’an 710071, China
4 Songshan Lake Materials Laboratory, Dongguan 523808, China
5 CAS Center for Excellence in Ultra-intense Laser Science, Shanghai 201800, China
We demonstrate nonlinear pulse compression of an 8 kHz Nd: picosecond laser using the multi-pass-cell (MPC) technique with fused silica as the nonlinear medium. The pulse duration is compressed from 12.5 ps to 601 fs, corresponding to a pulse shortening factor of 20.8. The output pulse energy is 154 μJ with an efficiency of 74.5%. To the best of our knowledge, this is the highest pulse compression ratio achieved in a single-stage MPC with bulk material as the nonlinear medium. The laser power stability and the beam quality () before and after the MPC are also experimentally studied. Both the laser power stability and the beam quality are barely deteriorated by the MPC device.
multi-pass cell Nd:YVO4 compression ratio femtosecond laser Chinese Optics Letters
2021, 19(9): 093201
Author Affiliations
Abstract
1 Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
2 University of Chinese Academy of Sciences, Beijing 100049, China
3 Songshan Lake Materials Laboratory, Dongguan 523808, China
4 School of Physics and Optoelectronic Engineering, Xidian University, Xi’an 710071, China
We demonstrate a harmonically pumped femtosecond optical parametric oscillator (OPO) laser using a frequency-doubled mode-locked Yb:KGW laser at a repetition rate of 75.5 MHz as the pump laser. Based on a bismuth borate nonlinear crystal, repetition rates up to 1.13 GHz are realized, which is 15 times that of the pump laser. The signal wavelength is tunable from 700 nm to 887 nm. The maximum power of the signal is 207 mW at the central wavelength of 750 nm and the shortest pulse duration is 117 fs at 780 nm. The beam quality (M2 factor) in the horizontal and vertical directions of the output beam are 1.077 and 1.141, respectively.
GHz femtosecond laser optical parametric oscillator tunable wavelength Chinese Optics Letters
2020, 18(3): 033201
1 光纤通信技术和网络国家重点实验室, 湖北 武汉430074
2 武汉光迅科技股份有限公司, 湖北 武汉430205
设计了一套自动化测试系统, 该系统能方便地测试MEMS-VOA(基于微机电系统的可变光衰减器)的所有指标, 还可以实现光谱仪与偏振控制器的测试共享。通过编程, 能实时显示数据与绘制曲线, 并将数据自动存储到数据库。与标准的测试仪表相比, 该测试系统造价低廉, 准确度较高, 具有很高的应用价值。
基于微机电系统的可变光衰减器 自动化测试系统 数据库 MEMS-VOA auto test system database
光纤通信技术和网络国家重点实验室 武汉光迅科技股份有限公司, 湖北 武汉430074
文章提出一种熔锥形透镜光纤的设计方法, 与常用的圆锥形保偏单模光纤相比, 熔锥形透镜光纤与超辐射发光二极管(SLED)管芯的耦合效率可由原来的45%提高到60%, 工作距离由7 μm达到超过15 μm, 且前者的耦合容差远远大于后者。对于新设计的熔锥形透镜光纤, 文章还给出了偏移和偏心与耦合效率的关系曲线图。
超辐射发光二极管 熔锥形透镜光纤 光纤耦合 耦合容差 SLED fused-cone lensed fiber fiber coupling coupling tolerance