Jones Travis, Peters William K, Efimov Anatoly, Sandberg Richard L, Yarotski Dmitry, Trebino Rick, Bowlan Pamela
Opt Express. 2020 Aug 31;28(18):26850-26860. doi: 10.1364/OE.402025.
We introduce a variation on the cross-correlation frequency-resolved optical gating (XFROG) technique that uses a near-infrared (NIR) nonlinear-optical signal to characterize pulses in the ultraviolet (UV). Using a transient-grating XFROG beam geometry, we create a grating using two copies of the unknown UV pulse and diffract a NIR reference pulse from it. We show that, by varying the delay between the UV pulses creating the grating, the UV pulse intensity-and-phase information can be encoded into a NIR signal. We also implemented a modified generalized-projections phase-retrieval algorithm for retrieving the UV pulses from these spectrograms. We performed proof-of-principle measurements of chirped pulses and double pulses, all at 400 nm. This approach should be extendable deeper into the UV and potentially even into the extreme UV or x-ray range.
我们介绍了一种互相关频率分辨光学门控（XFROG）技术的变体，该技术使用近红外（NIR）非线性光学信号来表征紫外（UV）波段的脉冲。采用瞬态光栅XFROG光束几何结构，我们利用未知紫外脉冲的两个副本创建一个光栅，并使近红外参考脉冲从中衍射。我们表明，通过改变创建光栅的紫外脉冲之间的延迟，紫外脉冲的强度和相位信息可以被编码到一个近红外信号中。我们还实现了一种改进的广义投影相位恢复算法，用于从这些光谱图中检索紫外脉冲。我们对啁啾脉冲和双脉冲进行了原理验证测量, 所有测量均在400nm波长下进行。这种方法应该可以扩展到更深的紫外波段，甚至可能扩展到极紫外或x射线范围。
