2D titanium disulfide (TiS₂) is recently found to have strong light absorption properties from visible to infrared (IR) region. This feature is highly attractive for applications in nonlinear photonics; however, the mechanism of broadband light–matter interaction is yet to be determined and nonlinear photonic devices are not developed. Here, for the first time, the experimental evidence supporting the mechanism of the broadband nonlinear photoresponse in ultrathin TiS₂ nanosheets ranging from 400 nm to 1390 nm is reported through laser Z‐scan measurements. High‐performance nonlinear photonic devices operating in the telecommunication band are also demonstrated. A novel saturable absorber (SA) device is successfully fabricated based on a 2D TiS₂‐decorated fiber, which exhibits outstanding ultrashort pulse generation performance with pulse duration of ≈1.04 ps centered at 1569.5 nm. Furthermore, as a stable all‐optical thresholding component, the device can effectively attenuate noise and boost the signal‐to‐noise ratio of the pulse from 1.90 to 10.68 dB. The findings indicate that TiS₂‐based SA devices can be developed into excellent highly nonlinear photonic devices, which may advance the development of TiS₂‐based optical communication technologies in the future.

中文翻译：

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超短脉冲产生和全光阈值设备的二维TiS2宽带非线性光响应

最近发现2D二硫化钛（TiS ₂）具有从可见光到红外（IR）区域的强光吸收特性。此功能对于非线性光子学中的应用极具吸引力。然而，宽带光-物质相互作用的机制尚待确定，并且非线性光子器件尚未开发。在这里，这是首次通过激光Z扫描测量报道了支持400nm至1390nm超薄TiS ₂纳米片中宽带非线性光响应机理的实验证据。还演示了在电信频段工作的高性能非线性光子器件。基于2D TiS ₂成功地制造了一种新型的可饱和吸收体（SA）器件装饰光纤，在1569.5 nm处的脉冲持续时间≈1.04 ps时，表现出出色的超短脉冲生成性能。此外，作为稳定的全光阈值组件，该设备可以有效地衰减噪声并将脉冲的信噪比从1.90 dB提高到10.68 dB。研究结果表明，基于TiS ₂的SA器件可以发展成为出色的高度非线性光子器件，这可能会在将来推动基于TiS ₂的光通信技术的发展。