A flat-amplitude multi-wavelength random Raman fiber laser with broad spectral coverage and a high optical signal-to-noise ratio (OSNR) is challenging and of great interest. In this Letter, we theoretically and experimentally proved that broadband pumping can help realize a broader, flat-amplitude multi-wavelength random Raman fiber laser. The influence of pump bandwidth, tunability of the spectral envelope, and channel spacing are investigated. As a result, with a 40 nm pump bandwidth, a spectral coverage of 1116–1125 nm with 19 laser lines and 31 dB OSNR is achieved, and the standard deviation in the peak intensities of the central nine lines is ${\sim}{1}.{1}\;{\rm dBm}$. This technique can also be applied to the multi-wavelength Raman (or random Raman) fiber lasers at other wavelengths and provide a reference for multi-wavelength applications in sensing, communication, and optical component testing.

中文翻译：

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宽带泵浦可实现平幅多波长随机拉曼光纤激光器

具有宽光谱覆盖范围和高光信噪比（OSNR）的平幅多波长随机拉曼光纤激光器具有挑战性，引起了人们的极大兴趣。在这封信中，我们在理论上和实验上证明了宽带泵浦可以帮助实现更宽广的，平坦振幅的多波长随机拉曼光纤激光器。研究了泵浦带宽，频谱包络的​​可调性和通道间隔的影响。结果，在40 nm泵浦带宽的情况下，利用19条激光线和31 dB OSNR可获得1116–1125 nm的光谱覆盖范围，中央9条线的峰值强度的标准偏差为$ {\ sim} { 1}。{1} \; {\ rm dBm} $。该技术还可以应用于其他波长的多波长拉曼（或随机拉曼）光纤激光器，并为传感，通信和光学组件测试中的多波长应用提供参考。