共查询到20条相似文献,搜索用时 109 毫秒
1.
X. L. Wang P. Zhou Y. X. Ma H. T. Ma X. J. Xu Z. J. Liu Y. J. Zhao 《Laser Physics》2010,20(6):1453-1458
We demonstrate a scalable architecture for coherent combining of all-fiber pulsed lasers with hybrid phase control involving
passive phasing and active phasing for the first time. Synchronized and passive phased pulsed laser array is built by intra-activity
phase modulation. Active phase control on the passive phased pulsed laser array using stochastic parallel gradient descent
algorithm provides stable in-phase coherent beam combining pattern in a turbulent atmosphere. The fringe visibility is increased
from 0 two 0.43 and the power encircled in the main-lobe is 1.616 times increased when the system evolves from passive phasing
to hybrid phasing. The architecture can be easily scaled up to high power by increasing power of each individual laser, number
of laser elements and introduction of power amplifiers, which will lead a promising way for scaleable high power coherent
beam combining of pulsed lasers. 相似文献
2.
We present a new approach for simultaneous spectral and coherent combining in a master oscillator power amplifier (MOPA) configuration with active phasing. Spectrally combined single-frequency seed lasers are employed as a master oscillator for the all-fiber power amplifier chain, which provides robust performance suppressing of the stimulated Brillouin scattering effect, while coherent combining of spectrally combined amplifiers with active phase control provides stable in-phase combining, despite the strong phase fluctuation. In experiments, two spectrally combined seed MOPA chains are coherently combined with a total output power of 390 W. The power of the main lobe in the closed loop is two times of that value in the open loop, and visibility of more than 75% of the long-exposure interference pattern at the receiving plane is obtained. 相似文献
3.
采用多抖动相位控制方法实现了两路和三路1 W量级光纤放大器的相干合成,对实验结果进行了详细分析。实验中,将种子光源输出激光分为两路(或三路),分别通过光纤放大器进行功率放大,并采用多抖动法实现相干合成。控制系统开环时,远场光斑条纹模糊不清,两路和三路合成时条纹对比度分别为0.19和0.12;系统闭环时,远场光斑条纹清晰可见,对比度提高到0.93和0.81,合成效率分别为80%和77%。此外,对两路和三路的合成效果进行了比较,指出了各路的控制资源对合成效果的影响。 相似文献
4.
Coherent Beam Combination of Two Polarization Maintaining Ytterbium Fibre Amplifiers 总被引:10,自引:0,他引:10 下载免费PDF全文
We investigate coherent beam combination of fibre laser beams by phase locking. Phase noise of a polarization maintaining ytterbium fibre amplifier is inspected with a fibre interferometer. In a feed back control loop, two fibre polarization maintaining ytterbium amplifiers are phase locked and coherent combined when the phase noise is properly controlled by a LiNO3 phase modulator. 相似文献
5.
Coherent beam combining of two fibre amplifier chains with a total power of 260 W in a compact system using the stochastic parallel gradient descent (SPGD) algorithm is demonstrated. A 150 MHz linewidth fibre laser is built and introduced for high-power amplification to mitigate stimulated Brillouin scattering (SBS). Compact high-power amplifier chains are built with low power all-fibre system and high-power bulk free-optics fibre amplifiers. When the total power is about 260 W, active phase-locking of two high-power amplifiers is demonstrated using the SPGD algorithm. In closed-loop, the power in the main lobe increases 1.68 times, the visibility is increased from 0 to 0.62, and the phase residual error is less than λ/10. 相似文献
6.
We demonstrate coherent beam combining of two
tiled-aperture single-frequency fibre amplifiers with a total output
power of 29.65~W by using the multi-dithering technique. The two laser
beams are packaged closely by using free-space mirrors side by side
into a tiled-aperture with a near-field fill factor of 62\%.
Active phase control of the amplifier is performed on commercially
available digital lock-in amplifiers. Experimental results show that
the power contained in the main-lobe in closed-loop is 1.72 times greater
than that in open-loop, which is 86\% for the ideal case. The
fringe contrast of the far-field fringe pattern is as high as 80\%
when the system is in closed-loop. The beam quality of the combined beam
is computed to be BQ = 1.48. The whole system in closed-loop performs
well in a long-time observation. 相似文献
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9.
Wenbo Du Xiaolin Wang Yanxing Ma Jiajian Zhu Xiaolin Dong Pu Zhou Xiaojun Xu Bohong Shu 《Optics & Laser Technology》2012,44(1):247-250
Seeding high power fiber amplifier employing multi-tone fiber laser is an effective approach to suppress stimulated Brillouin scattering (SBS). In this paper, a two-stage 1064 nm high power fiber amplification system was set up. Single-, two- and three-tone fiber lasers were employed. SBS threshold powers and maximum output powers of the multi-tone cases are enhanced compared with the single-tone case. The multi-tone amplifiers also show comparable optical-to-optical efficiency to the single-tone amplifier. To demonstrate and validate coherence property of the two multi-tone fiber amplifiers, the output laser beams of the amplifiers were self-interfered in our self-made coherent beam combining system. The laser beams of the multi-tone cases showed good coherence property comparable to the single-tone case, which implied that the high power output laser light of the multi-tone fiber amplifiers could be used for coherent beam combining. 相似文献
10.
Coherent combination of high-power, zigzag slab lasers 总被引:14,自引:0,他引:14
Goodno GD Komine H McNaught SJ Weiss SB Redmond S Long W Simpson R Cheung EC Howland D Epp P Weber M McClellan M Sollee J Injeyan H 《Optics letters》2006,31(9):1247-1249
We demonstrate a scalable architecture for a high-power, high-brightness, solid-state laser based on coherent combinations of master oscillator power amplifier chains. A common master oscillator injects a sequence of multikilowatt Nd:YAG zigzag slab amplifiers. Adaptive optics correct the wavefront of each amplified beamlet. The beamlets are tiled side by side and actively phase locked to form a single output beam. The laser produces 19 kW with beam quality <2x diffraction limited. To the best of our knowledge, this is the brightest cw solid-state laser demonstrated to date. 相似文献
11.
Numerical and experimental study on coherent beam combining of fibre amplifiers using simulated annealing algorithm 下载免费PDF全文
We present the numerical and experimental study on
the coherent beam combining of fibre amplifiers by means of simulated
annealing (SA) algorithm. The feasibility is validated by the Monte
Carlo simulation of correcting static phase distortion using SA
algorithm. The performance of SA algorithm under time-varying phase
noise is numerically studied by dynamic simulation. It is revealed
that the influence of phase noise on the performance of SA algorithm
gets stronger with an increase in amplitude or frequency of phase
noise; and the laser array that contains more lasers will be more
affected from phase noise. The performance of SA
algorithm for coherent beam combining is also compared with a widely
used stochastic optimization algorithm, i.e., the stochastic
parallel gradient descent (SPGD) algorithm. In a proof-of-concept
experiment we demonstrate the coherent beam combining of two 1083~nm
fibre amplifiers with a total output power of 12~W and 93%
combining efficiency. The contrast of the far-field coherently
combined beam profiles is calculated to be as high as 95%. 相似文献
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Coherent beam combining enables power scaling beyond the limits of single amplifiers. Therefore, improving the performance and simplicity of coherent combination techniques is of great interest for many high power applications. Here, we show all-fiber coherent beam combining of two ytterbium doped amplifiers with and without a dedicated phase actuator and a total output power up to 25 W. Instead of a dedicated phase actuator, we directly controlled the two ytterbium amplifiers to also stabilize their relative phase. We compared the performance of this method with phase stabilization using two piezo driven fiber stretchers. In both cases, power noise was dominated by the single amplifier. 相似文献
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Xiaolin Wang Yanxing Ma Bing He Yuhao Xue Zhen Li Jun Zhou Yijun Zhao 《Optics Communications》2011,284(8):2198-5536
We demonstrate coherent beam combining of two-dimensional fiber amplifier arrays with a total of 137 W output power using stochastic parallel gradient descent (SPGD) algorithm. Compact all-fiber polarization-maintained single frequency fiber amplifier chains are developed and four fiber amplifiers are arranged to 2 × 2 laser array with a fill factor of 70% in the near-field. Active phase control is implemented by a digital signal processor (DSP) based SPGD controller. The fringe visibility of the coherent combined beam profile is as high as 81% when the system is closed-loop controlled despite perturbations of the environment. 相似文献
16.
Active phase control in fiber amplifiers is of considerable interest for low-noise single-frequency amplifiers and for coherent beam combining. We demonstrate phase control at 1064 nm by use of an erbium-doped fiber. We investigated the phase shift by guiding the beam through an erbium-doped fiber amplifier in a Mach-Zehnder configuration and applied the results to stabilize the relative phase of two ytterbium-doped fiber amplifiers. To the best of our knowledge, this is the first demonstration of an all-fiber coherent beam combining at 1064 nm employing an erbium-doped fiber as a phase actuator. 相似文献
17.
由于受到受激布里渊散射(SBS)等非线性效应的限制,单频激光放大器的功率在百瓦量级,以非单频激光多波长激光作为种子源能够有效地抑制SBS并提高放大器功率.与单频激光相干合成相比,非单频率、多波长激光的相干合成有望将输出激光功率成量级地提高.基于随机并行梯度下降(stochastic parallel gradient descent,SPGD)算法,实现了四波长激光的相干合成.在系统闭环时,四路多波长激光合成后的主瓣能量能够提高3倍,达到理想值的75%.验证了多波长、非单频激光相干合成的可行性,为高功率相干合成的发展提供了新的途径. 相似文献
18.
We report on active coherent beam combining of two single-frequency nanosecond fiber amplifiers by using stochastic parallel gradient descent algorithm. Each fiber amplifier produces an average power of more than 100 W by using three-stage cascaded amplification. The two laser beams are actively phase-locked with a total average power of 215.8 W, producing ~8 ns pulses at 10 MHz repetition rate. The contrast of the far-field intensity pattern of the coherently combined beam is more than 83%. 相似文献
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研究了LaB6在1~10 Pa氮气和氦气中的直流和脉冲放电特性以及放电过程对电极的影响。结果表明,电极直径为5 mm的LaB6氦气放电管在脉冲工作状态下可以长期稳定放电。在脉冲电压为2.2 kV、脉冲宽度10 ms、频率13.3 Hz下,脉冲峰值放电电流超过120 A。氦气放电管在放电过程中,阴极表面有离子的清洗和活化作用,可以使电极的表面逸出功降低,提高放电管的发射能力和稳定性。LaB6作为气体放电电极具有寿命长、延迟时间短、放电电流大等优点,可用于重复强流脉冲气体放电的高压高速开关器件。 相似文献