We report an interesting observation of visible light flashes indicating pulsing events in Near Infrared fiber laser systems. Using a narrow-linewidth, continuous-wave (CW) fiber laser operating at 1064 nm, we observed visible flashes composed of faint, red, orange, yellow and green colors. Concurrently with the visible flashes, the spectra in the backward direction showed different Raman Stokes orders of 1064 nm for a silica medium. We attribute this form of visible light generation to Cherenkov-type phase-matched harmonic generation in optical fibers enabled by high-peak-power parasitic pulses. These pulses are attributed to the onset of stimulated Brillouin scattering. The harmonics of different Raman Stokes orders of the pulses are responsible for the different visible colors observed. This effect is potentially observable in any laser system with a high optical power with a CW, quasi-CW or pulsed form.

我们报告了一个有趣的可见光闪光观察，表明近红外光纤激光系统中的脉冲事件。使用工作在 1064 nm 的窄线宽连续波 (CW) 光纤激光器，我们观察到由微弱的红色、橙色、黄色和绿色组成的可见闪光。在可见闪光的同时，反向光谱显示出二氧化硅介质的不同拉曼斯托克斯级数为 1064 nm。我们将这种形式的可见光产生归因于高峰值功率寄生脉冲在光纤中产生的切伦科夫型相位匹配谐波。这些脉冲归因于受激布里渊散射的开始。脉冲的不同拉曼斯托克斯阶次的谐波是造成观察到的不同可见颜色的原因。