We demonstrate a novel method to optically tune the pulse advancement and delay based on stimulated Raman gain in hydrogen. With a frequency-chirped pump, the generated signal pulse is selectively amplified at the leading or trailing edge of the pump pulse, depending on whether the frequency difference between the pump and the signal beam is blue or red detuned from the Raman transition, which results in advancement or delay of the signal peak. Different from the method of slow/fast light, where advancement and delay are accompanied with power loss and gain, respectively, for a single resonance, both the advancement and delay are realized in the gain region for the method here. With a piece of 48-mm-long optical nanofiber in hydrogen, the time-shift for a signal peak ranging from 3.7 to −3.7 ns is achieved in a Raman-generated pulse with width of ${\sim}{12}\;{\rm ns}$.

中文翻译：

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光学纳米纤维通过频率chi刺激的拉曼增益可调节脉冲的前进和延迟

我们展示了一种新颖的方法，可以根据氢中受激拉曼增益光学调节脉冲的前进和延迟。对于频率chi泵浦，所产生的信号脉冲在泵浦脉冲的前沿或后沿被选择性放大，具体取决于泵浦和信号束之间的频率差是从拉曼跃迁失谐还是蓝色或红色，从而导致提前或延迟信号峰值。与慢/快光方法不同，对于单个谐振，提前和延迟分别伴随着功率损耗和增益，而提前和延迟均在此处的方法的增益区域中实现。使用一块长度为48 mm的光学纳米纤维在氢气中，可以在拉曼产生的脉冲中获得宽度为3.7到-3.7 ns的信号峰的时移。$ {\ sim} {12} \; {\ rm ns} $。