共查询到20条相似文献,搜索用时 15 毫秒
1.
For what we believe to be the first time, mask restoration in a backscattered signal in a highly non-steady-state regime of stimulated Brillouin scattering was attained. A special two-lens system of laser beam insertion into a scattering medium was used. Results are compared with those of ordinary one-lens focusing. 相似文献
2.
Jinyong Leng Shengping Chen Wuming Wu Jing Hou Xiaojun Xu 《Optics Communications》2011,284(12):2997-3003
High power operation of single-frequency Raman fiber amplifiers is usually limited by the onset of stimulated Brillouin scattering. A theoretical investigation on single-frequency Raman fiber amplifier limited by stimulated Brillouin scattering is presented in this paper, based on the intensity equations combining stimulated Brillouin scattering and stimulated Raman scattering. A combination of methods is proposed to increase the output power of single-frequency Raman fiber amplifier. These methods include applying a suitable pump scheme according to the fiber length and seed signal power, using short gain fibers, utilizing a multiple-stage scheme and providing suppression of stimulated Brillouin scattering. 相似文献
3.
J. Shi X. Chen M. Ouyang W. Gong Y. Su D. Liu 《Applied physics. B, Lasers and optics》2012,106(2):445-451
The pumping effect of stimulated Brillouin scattering on stimulated Raman scattering is investigated theoretically through
the coupled wave equations of stimulated Brillouin scattering and stimulated Raman scattering. The numerical simulations are
in agreement with the experimental results. They indicate that the backward stimulated Raman scattering is excited and amplified
collectively by both pump laser and stimulated Brillouin scattering. 相似文献
4.
S波段光纤拉曼放大器中级联受激布里渊散射串扰的实验研究 总被引:2,自引:0,他引:2
研究了光纤激光器前向抽运的S波段分布式光纤拉曼放大器中级联的受激布里渊散射(SBS)串扰现象。用窄光谱带宽(<100MHz)的可调谐激光二极管作为信号源,通过S波段分布式光纤拉曼放大器,当被放大的信号功率超过单模光纤受激布里渊散射的阈值时,出现了前向受激布里渊散射,这是传导声波布里渊散射在光纤放大器中放大的现象。随着拉曼放大器抽运功率的提高,在斯托克斯区,出现了两阶受激布里渊散射线,在实验中观测到偶数阶的受激布里渊散射谱线功率大于奇数阶的布里渊一瑞利散射线。当进一步增加拉曼放大器的抽运功率,出现了前向级联的多阶受激布里渊散射现象,拉曼放大器的增益下降,被放大的信号功率转换为受激布里渊散射,噪声变大。受激布里渊散射的串扰破坏了拉曼放大器的特性,使拉曼放大器无法在密集波分复用光纤传输系统中使用,因此需要严格地控制入纤的信号功率和放大器的抽运功率。在实验中还观测到在光纤拉曼放大器中被放大的信号光和受激布里渊散射线两侧的伴线。 相似文献
5.
报道了基于神光Ⅱ激光装置的全口径背向散射测量系统。系统通过激光聚焦透镜收集激光等离子体相互作用产生的散射光;两个热能量卡计分别测量波长348~354 nm范围的受激布里渊散射和波长400~700 nm范围的受激拉曼散射产生的散射光。该系统可以测量散射光的能量、功率和光谱图像,提供优于0.5 nm光谱分辨和10 ps时间分辨的光谱物理信息。同时采用PIN二极管阵列对聚焦透镜外侧附近的近背向散射光信息进行测量。 相似文献
6.
7.
A period-eight cycle route to chaos has been observed in a stimulated Brillouin scattering (SBS) system for the first time. Since the observation of fine periodic-orbit structure in very short dynamical region of chaotic domain is very difficult, in this work, we design a novel experiment to extend the chaotic domain by injecting light to the end of fiber and adjusting the proportion of stimulated Brillouin backscattering power and pump power, the present result shows the period-eight cycle route to chaotic laser process as well as more details of chaos. Simulations of the route to chaos are also presented. 相似文献
8.
9.
《Optics Communications》2003,215(1-3):163-167
A new short-pulse KrF laser source was developed by combining stimulated scattering processes, namely, Raman, Brillouin, and four-wave-mixing (FWM). Short pulses of 1.1 ps were obtained from 4 ns oscillator output. Only two commercial discharge KrF lasers are required for this system. This method is very simple and could be extended to an ArF laser wavelength in principle. 相似文献
10.
Salhi M Hideur A Chartier T Brunel M Martel G Ozkul C Sanchez F 《Optics letters》2002,27(15):1294-1296
We have designed and performed an experiment that permitted direct observation of Brillouin backscattering in an Yb-doped double-clad fiber laser. Fifteen Brillouin-shifted frequencies were observed for the first time to our knowledge. We clearly demonstrate that stimulated Brillouin scattering is directly responsible for both fast transient dynamics of the laser and reduction of the laser's pulse width. 相似文献
11.
Da-he Liu Jin-wei Shi Xu-dong Chen Min Ouyang Wen-ping Gong 《Frontiers of Physics in China》2010,5(1):82-106
The principle of a lidar based on Brillouin scattering is introduced. The basic physics of the Brillouin lidar is discussed.
The applications of the Brillouin lidar in remote sensing of the ocean, such as measurement of the sound speed and the bulk
viscosity of water and detecting submerged objects are investigated. An actual Brillouin lidar system is developed. Also,
several basic problems related to Brillouin lidar are studied in detail. The attenuation coefficient of a pulsed laser beam
with high pulsed energy in water is investigated; it is helpful to reveal the propagation property of a laser beam in water.
The investigations on the threshold value of SBS are made theoretically and experimentally. Finally, a novel phenomena is
investigated experimentally, in which Stimulated Raman scattering can be enhanced by stimulated Brillouin scattering. 相似文献
12.
A single-mode polarization-maintaining fiber doped to increase the Raman gain while suppressing stimulated Brillouin scattering (SBS) was utilized in a single-stage counter-pumped Raman fiber amplifier. The SBS suppression was achieved through the acoustic tailoring of the core. A pump probe experiment was conducted to characterize the Brillouin gain and indicated the existence of multiple Brillouin peaks. When the amplifier was seeded with approximately 15 mW of 1178 nm light, 11.5 W of cw output power was obtained with a linewidth ≤2 MHz. The application of a thermal gradient to further mitigate the SBS process increased the output power to 18 W, thus providing a net amplifier gain >30 dB. 相似文献
13.
14.
本文介绍了近二年来我国在用喇曼散射和布里渊散射研究半导体、金属及半导体超晶格,高温超导体、磁性物质和介电晶体等方面的进展,以及表面增强喇曼和受激光散射研究的进展情况。 相似文献
15.
Stimulated Brillouin scattering is studied by numerically solving the Vlasov-Maxwell system. A cascade of stimulated Brillouin scattering can occur when a linearly polarized laser pulse propagates in a plasma. It is found that a stimulated Brillouin scattering cascade can reduce the scattering and increase the transmission of light, as well as introduce a bursting behaviour in the evolution of the laser-plasma interaction. The bursting time in the reflectivity is found to be less than half the ion acoustic period. The ion temperature can affect the stimulated Brillouin scattering cascade, which can repeat several ×at low ion temperatures and can be completely eliminated at high ion temperatures. For stimulated Brillouin scattering saturation, higher-harmonic generation and wave-wave interaction of the excited ion acoustic waves can restrict the amplitude of the latter. In addition, stimulated Brillouin scattering cascade can restrict the amplitude of the scattered light. 相似文献
16.
提出了一种新型的由熔石英棒和石英光纤组成的复合型相位共轭镜,其可运用于高重复频率激光输入系统中以改善光束质量.该复合相位共轭镜具有较高的受激布里渊散射反射率和受激布里渊散射损伤阈值以及较低的受激布里渊散射阈值等优点.实验中,在100 Hz重复频率下,最大获得了42.05%的受激布里渊散射反射率.根据实验条件,由耦合波方程及边界条件得到的物理模型,经数值求解后得到的结果和实验符合较好.且由理论结果提出了一种提高该复合型相位共轭镜工作状态的有效方法.
关键词:
复合型相位共轭镜
受激布里渊散射
熔石英
耦合波方程 相似文献
17.
18.
The amplification effect on stimulated Brillouin scattering (SBS) and Rayleigh scattering in the backward pumped G652 fiber Raman amplifier (FRA) is studied. The pump source is a 1427.2-nm fiber Raman laser whose power is tunable between 0 - 1200 mW, and the signal source is a tunable narrow spectral bandwidth (〈 10 MHz) external cavity laser (ECL). The Rayleigh scattering lines are amplified by the FRA and Stokes SBS lines are amplified by the FRA and the fiber Brillouin amplifier. The total gain of SBS lines is the production of the gain of Raman amplifier and that of Brillouin amplifier. In experiment, the SBS gain is about 42 dB and the saturation gain of 25-km G652 backward FRA is about 25 dB, so the gain of fiber Brillouin amplifier is about 17 dB. 相似文献
19.
20.
In the present work volume real image reconstruction at the Stimulated Raman Scattering (SRS) of the object, illuminated by laser light, has been observed experimentally for the first time in the large wavelength diapason. The thresholds and exciting power density intervals for observation of the reconstruction differ for different wavelengths and kinds of stimulated scattering. The image reconstruction at stimulated scattering has been shown to be consequence of the wavefront reconstruction effect at SRS, revealed by the authors in 1970. The phenomenon of the image reconstruction at stimulated scattering has some common features with the holograms registration and reconstruction, but there is no known holography method, quite similar to the discovered effect. 相似文献