通过轨道角动量模式分割滤波实现受激布里渊放大的低噪声和高增益

Low-noise and high-gain of stimulated Brillouin amplification via orbital angular momentum mode division filtering.

作者信息

Sheng Liwen, Ba Dexin, Lu Zhiwei

出版信息

Appl Opt. 2019 Jan 1;58(1):147-151. doi: 10.1364/AO.58.000147.

DOI:10.1364/AO.58.000147

Abstract

We demonstrate a Brillouin amplifier scheme by using orbital angular momentum mode division filtering, which is able to amplify the weak optical signals with low noise and high gain. The system retains the advantages of a conventional collinear Brillouin amplifier structure, and employs a liquid-crystal spatial light modulator to generate distinguishable degree-of-freedom of beams. As we all know, the noise mainly derives from the unwanted coupling in stimulated Brillouin scattering (SBS) processes, which severely limits the amplifier's performances. The efficient SBS noise-filtering method is discussed, which could improve the output beam quality effectively. The experimental results show the proposed amplifier scheme can overcome this obstacle, providing the magnification (or called signal gain) of 71 dB for an input signal of 4.7×10 J. In addition, the amplified signal is recognized from the amplifier spontaneous-emission (ASE)-like noise with a signal-to-noise ratio of 6.7 dB.

摘要

我们展示了一种利用轨道角动量模式分割滤波的布里渊放大器方案，该方案能够以低噪声和高增益放大微弱光信号。该系统保留了传统共线布里渊放大器结构的优点，并采用液晶空间光调制器来产生可区分的光束自由度。众所周知，噪声主要源于受激布里渊散射（SBS）过程中的有害耦合，这严重限制了放大器的性能。讨论了有效的SBS噪声滤波方法，该方法可以有效提高输出光束质量。实验结果表明，所提出的放大器方案能够克服这一障碍，对于4.7×10 J的输入信号，提供71 dB的放大倍数（或称为信号增益）。此外，放大后的信号能够从类似放大器自发辐射（ASE）的噪声中识别出来，信噪比为6.7 dB。