The theory of Hawking radiation can be tested in laboratory analogues of black holes. We use light pulses in nonlinear fiber optics to establish artificial event horizons. Each pulse generates a moving perturbation of the refractive index via the Kerr effect. Probe light perceives this as an event horizon when its group velocity, slowed down by the perturbation, matches the speed of the pulse. We have observed in our experiment that the probe stimulates Hawking radiation, which occurs in a regime of extreme nonlinear fiber optics where positive and negative frequencies mix.

中文翻译：

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光学模拟中受激霍金辐射的观察

霍金辐射理论可以在黑洞的实验室类似物中进行测试。我们在非线性光纤中使用光脉冲来建立人工事件视界。每个脉冲通过克尔效应产生折射率的运动扰动。当其组速度（由于扰动而减慢）与脉冲速度匹配时，探测光将其视为事件范围。我们在实验中观察到，该探头会激发Hawking辐射，该辐射发生在极端非线性光纤中，正负频率混合。